I just put together the same system you recommended with a 250A smart-BMS with bluetooth. All cells (4x280ah) were bottom and top balanced (per Will P.) recommendation. Individual cells were top out at 3.6v in parallel then ensembled together in series with BMS. Prior to charging, all cells were balanced to around 3.337v - 3.410v. Once I started the low amp (5amps) charge, one of the cell was starting to gain in voltage faster than the other 3 cells rapidly (within 20min). I was able to monitor this via bluetooth in realtime to see the voltage gain across all 4 cells. Smart-BMS kicked in around 3.65v for the upper limit fault condition of the defective cell. It started to balance out the rest of the cells; however, its total voltage hit the upper limit as well for the Renogy charger. So the rest of the 3 good cells were topped out around 3.4v. Total Ah was around 250ah due to the defective cell (280Ah advertised). I am currently working with the vendor to replace the defective cell. Not sure how it will turn out but at least they have accepted the results that I provided. it definitely worth $ to invest in a smart BMS (even a 20A model) just to make sure you have good cells prior to install it permanently. Will P. has some good recommendation. I am currently working out some installation bugs (bluetooth and connections) with the BMS provider (may even request to refund or exchange). The technical support level from these manufacturers are non-existence. YOU ARE ON YOUR OWN.
Dan! I'm pumped that you actually got 282.4AH out of your 'cheap Chinese' batteries!!! Yay for us! Now, I'm not afraid that I'm gonna over charge or over-discharge them (I'm using (2) either @ 12v or 24v) and can't ever see a reason why I'll ever need more than 280AH draw- all at once. BUT, I notice that the AL cases seem to bow out a lil on the face? You built a box, but, I need to strap them, or, tape them to hold the cell together. I plan on using (4) 1" squares of double sided VHB tape used in the corners to hold the cell together- twice. After sort of 'holding them together' with the VHB tape, I'll either strap them by hand, or, tape them together. I'm a little concerned about the weight of (4) cells VHB'd & taped together, as I think each battery weighs 47 Lbs. I do NOT want to strip those teensy, tiny lil M6 bolts out of the anode and/or cathode, so, I prefer the least strain on that connection as possible.
That is exactly what I was worried about too. I had it originally taped together and connected with the bus bars that came with the cells. Then I realized that if the walls swelled in the heat of summer, the bus bars won't give it any room to flex and push away from each other. That's why I chose to add foam between each cell and make my own longer bus bars. The m6 terminals are definitely the weakest part of these otherwise great batteries.
Dan- I totally agree, and, I really like the foam insert between cells. That way you choose which length to make your buss bars, and, no matter how much stress- the M6 bolts are free. I'd prefer to have the cells tightly linked together (size & footprint), and- on genuine consideration of draws & loads, I NEVER think I'll ever get over 100 Amp draw. I'm using (2) either in 12v or probably 24v and DON'T plan on running my 11,000 BTU A/C off of it. Even the 'on-board' heating system doesn't draw that much. Croatia- talk about overcoming issues, in a small town, remotely located & yet- still able to git 'R done! Awesome work, my friend!
Great videos. Trust your readings from the Victron shunt. I have the BMV-712 and have been using since August 2019. I have the 500AMP shunt. Trust me when I say the calibration of your shunt is dead on the money. I have never seen a Victron shunt needing any field calibration. Good idea you have for making your battery last a life time. The 10%-90%. I use 80%-20% as my marker. Really appreciate all your hard work and your sharing of info. It's been a longtime since I have spoken to Croatia, I'm a ham radio operator. Call sign NF7T in the USA.
I agree trust the victron. Some of those cheaper "ebay/aliexpress" power meters assume 12V and don't actually measure the voltage. From your video, you say it's reporting 157W 157/12 = 13.08A which is similar to what your victron was reporting. I have one of those cheaper power meters and it's only really useful for current in/out (unless you have exactly 12V).
Awesome video Dan, I like how you keep the camera steady, talk normal and don't play loud background music. After watching your video, I'm wondering if the Victron Smart Shunt is trully necessary as it seems to replicate what the Daly BMS gives you through their bluetooth app. I guess it's because you're using a Victron Charger and it integrates the monitoring through bluteooth? Having the little cell monitor is however truly useful as it provides instant visual feedback - inexpensively!... After 8 days of self balancing, my 16 paralleled cells stabilized at 3.47 V. I was tempted to recharge them back to 3.65 V, but I'm glad i watched your video as I realized it's not needed before assembling them as a 48V battery. I'll attach a Heyo bluetooth 320A BMS with 1A active balancing (Daly) to perform the discharge test as you did. I'll also set the BMS to 2.8V just like you did as I feel no need to push it down to the knee. Hopefully I'll also get close to 282 Ah too. I strongly doubt that I got true grade A cells, but it's not so important. What's important, is to maintain a close to 5 mV balancing differential between cells. However I realize that getting this close balancing is more of a BMS function than cell performance, as well as giving enough idling time for the BMS to do it's passive balancing. I'm actually getting down to 1 to 2 mV at time with the ANT BMS in spite of the fact that a couple of my cells (on my second battery) are running away. Indeed, the BMS intermittently shuts off with High cell Protect level 2 warnings every time the charger injects more power into it. i can see the voltage on those 2 cell spiking to 4.5V! Thanksfully the BMS shut the charging FETs OFF. These same 2 cells also trigger the Low level 2 cell protect cut off. So it's time to take the battery apart and test those 2 cells or perhaps text the FETs on the BMS. Wish me luck and thanks for your videos! Keep up the good work Dan.
Thank you Sir! I just bought my batteries in AliExpress and will be procuring the other parts for the build. I will be using my battery when overlanding.
Don, what a great video series!! Thanks a lot for taking the time to do it. I was checking at AliExpress an 8 batteries kit all the way from China to Puerto Rico, as it was the only option available for me, but the shipping cost was the same as the batteries'. I think I'll have to continue searching for other options. Any comment will be appreciated.
Wow that's crazy. If you click on the link for the batteries again in my description, you will see a lot of other vendors also selling them perhaps try a few different ones and see if that makes a difference.
Honestly, I enjoyed your video, very informative, please disregard any negative comments, like you said it's a free country.. nobody is forcing anyone to watch...
The voltage drops logarithmically as you discharge LiFePo4 cells. That’s why the voltage acts a little bit differently than what you’ve probably seen before. Great video!
yes this is great info and seems to be the best value/AH---- i am trying to set up a backup to run my 17cf frig for 2 or 3 days during a Hurricane power outage- this looks like the answer!!!
Really nice build you did there and want to attemp the same thing....We live out in the Sonoran Desert of Arizona and when those temps get up into the mid 115 +/- I have found no tape that doesn't give out in that heat including that 3M stuff.. Screws into the wood with small washers up top should hold it in place
Dan - thanks for taking the time - this is the second of your videos that I've checked out. Subscribed, and hoping you share more of our adventures! It isn't just the knowledge you impart: I get nostalgic for the 18 months I spend living from a Toyota Landcruiser (troopy, we call them in Australia). Had just an 80w panel and single deep cycle battery back then, but it was enough to run a small Engel fridge, and keep my gadgets charged. Quick question if I may: I'm speccing out a house solar setup for a remote island, and am very focused on longevity for the batteries in case sourcing new ones is a problem in the future. This might sound a bit extreme, but I'm currently thinking of keeping the state of charge between 25 and 75 percent, leaving only 50% capacity to actually use. I'll double the battery bank capacity to compensate. So I was really interested in understanding your safety margin and how it compares to your 282ah result? Sooo, the question: when the Victron shunt shows 100% SOC at the outset, does that mean 100% of the 90% maximum charge as per your longevity margin, or does it mean absolute 100%? I imagine it means absolute 100% SOC, since your result of 282ah is already above the rated capacity of your cells? Likewise, I imagine that 0% according to the shunt corresponds to complete discharge, without including the 10% longevity margin, for the same reason? What confused me a bit is that you did go into some interesting detail about how the low voltage cutoff for the BMS is 2.8v +-0.05v. That seems like a generous protection margin already, so does it include the 10% buffer you mentioned you want on the low end? In which case could we consider the overall capacity of your cells to be even higher than 282ah? Are you going to be relying on the BMS for setting your custom margins (does it allow custom settings)? Or are you going to program that into the Victron shunt? Or will your charger allow custom settings? Happy trails!
Great and informative series. I love the intro of all your videos. Watching it all however made me skeptical, the amount of money and time spent and the longevity of the batteries. Is it really all that worth the hassle?
Thanks. Whether or not it's worth the hassle depends completely on the person. If you are not the DIY type then it's probably not for you. This battery will last 10+ years. I've been using it already for 2 years and there are no signs of degradation. If you just want to buy an off the shelf battery, they are available these days for a lot less than they were before. DIY will still be cheaper but the gap is narrowing.
I have 16 of these cells on their way and I have been trying to figure out the best way to mount them. I had considered using the shipping foam but I was a bit afraid of overheating the batteries under high load. That is certainly something Id be paying attention to.
The victeon battery sense is best placed in between the cells to more accurately measure the temperature of the cells when you are charging them. The charger will then use the entered temperature coefficient value to modify the charge rate.
Temperature compensation is disabled in my Victron chargers. The battery sense is used for low temp disconnect. You can see how this has been reconfigured in my cold weather modifications series.
be very careful leaving that hobby "Capacity meter" powered full time. The reason is that it pulls it's power from cell 1, meaning it will slowly drain that one cell just to "keep it's lights on" hope this helps.
Since the BMS and the active balancer are both keeping the cells in balance, the miniscule draw from cell 1 will never be an issue. It will practically instantly be balance with the other cells. All of the components I'm using all will put a small load on the pack as well. The bms, active balancer, shunt, temp sensor all run at net negative power. But it would take many months to parasitically drain this pack.
I capacity tested a small battery last night, I used a capacity meter, and 200watts of led flood lights, the house was flooded with light last night! Ha-ha, the pack came to about 20ah, my 33kwh house battery is not going to be easy to verify, ha... That's over 1k ah. I have 3400w of panels to put up also, I hope to get more battery, and more solar, and build some type of ev, even if it's only a electric tricycle! A 20"-24" trike, with 2, 5kw motors, and a 1.5-3kwh battery would be a mean macheen! I do have enough cells to build a 32ah 28s battery for a small e bike, to be charged from my off grid house power system!! So I can build a 48v, 60v, 72v or even 96v, maybe a 120vdc, and the cells are capable of a sustainable 200amps each, so 4p would be insanity for a E bike, a bit off topic, and rambling sorry!!
I watched your video (and subscribed) with great interest. I am a newbie to lithium. I took out two 12v AGMs replacing them with one 12v 170 Ah "Big Battery"with the Anderson connectors. I bought a Progressive Dynamics 9100AL lithium 60amp charger. What's new to the mix is the Victron Smart Shunt followed you kink. ...I'm just not sure what parameters to put in....so I copied yours I charged the battery for 24 hours it showed 14.5 V. I added all the components together on my work bench. Hooked up a 1000 inverter, plug in two 150w flood lights, clipped my Amp meter set on amps on the Positive cable into the battery and Multimeter on the Pos/neg out of the charger (just to double check) the I wired in the Smart Shunt, entered your parameters except battery amp hours. Discharged the battery until the inverter shut off at 10.5v. 169.5 amp hours showed on the connect app. When I took off the load and plugged the charger back in the connect app showed 100% SOC even though the battery and meter showed 13.2V that is 70% SOC according to the little chart you had. I manually changed the SOC to 70% and started charging again....WRONG OR RIGHT THING TO DO. In the mean time I will hang on your every word and intend to build a companion Battery when the funds allow. Keep on Keeping on. Happy New Year, Peace and Blessings, Richard
I would just charge your battery all the way up until the charger goes to float stage. Meaning there are no more amps going thru up in the charging wires. Then set the SoC in the app to 100%. That should give you a good place to start for all of your subsequent charge cycles. Just make sure that there are no loads in your system that isn't going thru the shunt so you are capturing everything.
Am I right in saying that your charge input mode (Noco) should be set as a standard "flat" feed? As you already have a BMS managing the charging, as well as a balancer, there's no need for a shaped current/voltage feed like the Noco's lithium option offers. All larger retail lithium batteries I have seen, for cars, motorbikes etc. state to use a "normal" charger, because the battery already contains the BMS circuit inside. You, in effect, have the same system. Food for thought.
I've learned that when charging LiFePO4 cell it's full when voltage here to 3.6 to 3.65 volts. That means 14.5 to 14.6 volts. When charger is stopped, voltage sets lower. Another important value is 20% remaining charge which when lightly discharged is 12.6 volts. I'm also tuning in my chinese battery monitor supervising GWL 12V 90Ah battery which doesn't have BMS...
Very well done. Please excuse me if I missed it but what did you end up with for a total build cost and how long did it take? Understanding that you did have some delays in sourcing. I'm more interested in working time.
Thank you Brian. So once I got all the parts the whole battery was built in an afternoon. But of course that is not counting the capacity testing time which took several days with a slow charger I had to use. The total build cost for me was around $1000. In the US you can get the same parts for about $800. In the next video I will outline them exactly for you guys.
right know for testing I have my 4 280ah cells in a plastic battery box for testing. Before I really start using it I need to clamp the batteries together, otherwise I read they can swell during heavy use and rip the terminals if the buss bars will not flex. Your factory bus bars are curved, and mine are straight leaving no room for flexing if and when the packs start to swell.
What are you planning to do with your battery? When you say heavy use, what will a typical day look like for these batteries? There is the normal expansion and contraction that happens with these cells when you charge and discharge that's completely harmless. Then there is repeated constant high c-rated draw that can generate enough heat causing excessive swelling which can lead to delamination of the internals. Like extensive use of induction cooktop or powering an air conditioner. The latter is what the compression technique is suppose to prevent. Mine will never be drawn beyond 0.2C so delamination should never be a problem. So my solution is to give the cells some added room to expand and contract naturally. I ditched the factory bus bars and made my own longer ones from copper pipes. It can be as little as using double sided foam tape between each cell to connect them then wrapping the with kapton tape on the outside. Your bus bar may provide enough wiggle room to allow that extra space. Also keep in mind that most factory build packs do not compress their cells tightly together like what some people are suggesting. The ideal solution for this problem depends a lot on how the battery will be used.
BTW towards the end around the 27 min mark I see at the distance what appears to be a Mazda Rx4 wagon, too far to distinguish... I owned many of the RE engine Mazdas from the 70s. Pound for pound they are little beasts.
Hi I've been watching your videos for past few hours, would this set up you did be ok with vibration from a car audio system? I plan on buying 90ah version of the batteries and looking at bms from bms overkill. Is there anything I should be concerned about due vibrations. Or taking anything into consideration? I plan on have the battery next to subwoofer box. Thanks for sharing your knowledge with others!
@8:36 you need to change the Peukert Exponent to 1.00 or 1.01 (It might not support 1.00). You have it set at 1.25 now which is for lead acids under high loads. The Peukert effect isn't applicable for LifePO4 batteries.
You will see in part 4 when I installed and programmed all the chargers in the camper is when I updated the Victron settings including setting the peukert constant. What you see in here are the defaults that came with the SmartShunt.
It's been a couple months now so when each step was done is getting a little fuzzy in my memory. But yes I understand peukerts law and how it effects the different battery types. Someone else has mentioned it before I installed it into the camper.
Hi, me again... Im all in to make a batyery bank for home use. My question is how many batteries cells can I parallel? I see you use 4 to make a 280A system, can I safely string more, or what would be a good fit for a home minus electric stove. Im still learning the math portion. Thank you Dan good day.😊
I'm assuming the Ah rating of your lithium batteries are a 20 hour rate. That means in order to truly test their capacity you'll need to apply a constant 14A DC load. Your original current was lower which is why you ended up with a higher capacity result.
If you read the spec sheet you can see that a 0.1C discharge doesn't give you much more capacity than a 0.2C discharge rate. Maybe I could squeeze 2-3 Ah more out of the 280 Ah rating at a lower discharge rate. Either way, these cells pulled the rated capacity as expected.
Did you "add" the house bank to the van ? You had mentioned 4 sources of charging, no mention of charging from the vans chassis alternator itself. If my RV has been wired to charge from the chassis alternator to the house battery, is the alternator charging parameter not good for the LiFe PO4 battery pack build you have just shown ? Right now my RV has 2 of the AGM 105 ah group 29's. So your build gets 280ah vs 210 ah , but the useable is so much greater. The RV does not have a dc to dc charger yet, but I will install one. Remove the alternator wire ?
I do not charge directly from the alternator but rather a dc to dc charger instead. Charging directly from the alternator without a current regulating charger can cause potential damage to the battery as well as the alternator itself.
Great video, I have one question I have a battery pack (Lithium Iron) connected to dash cam in my car. When vehicle is on the battery get recharge at 14.6V at 9 amps. It has an XT60 battery expansion port. I would like to know if I connect the above battery pack using the XT60 connector will the above battery charge and will be able to discharge back to main battery ?
thanks for the great videos... and a question... is there constantly a bluetooth signal coming from this battery box setup? or is there a way to turn it off?
No idea what getting property here is like. We have family land here going back a long time. I see real estate listings but have never talked to anyone about it. I do believe it is pretty expensive as compared to other Balkan countries. At least on the coast.
Hey thanks for sharing your setup, I was curious, does the position of the battery sense matter for accurately measuring the temperature you set for your low temp disconnect? Or is any mounting position fine as long as its close to the batteries?
Great video! Love it.. been using your vids to do something similar.. but do you know the recommended charge rate for the battery pack? I ended up with an expanded cell with using a 30a charge rate so that will be replaced.. but thinking it would be required to have the charge rate of the pack be aligned with the cell balancer.. if that's out of what, then would not one cell be charged more than the others or something to that nature?
also, the discrepancy that you are seeing comes from the fact that most meters don't include their OWN consumption, so depending where the meters are they include different things
As you might have seen from the video, there was never any discrepancy. what I saw was due to the refresh interval of the hobby capacity controller. It has a delay in the reading and is refreshed when the buttons are pressed. The reading are actually exactly the same. The amount of power consumption is really insignificant with a battery this size. It may matter with a small lipo cell but with this 3,600Wh pack, their consumption is virtually undetectable. We're talking sub-microvolt differences that none of my instruments are capable of reading.
Dan, GREAT VIDEOS! You're inspiring me to build my own also. I don't have time to read all the comments below, and I'm thinking that my question may be answered already. Just curious about getting all the other items besides the BMS and the cells. How many of them are necessary?
Am I the only one concerned that he's using cables that are color-coded as ground for power? Because that seems potentially dangerous. Otherwise very interesting; I expect I'll be using some similar cells soon, though in a different application.
Always test with a multimeter for polarity even if the cables are color coded. With DIY projects, you can't always get the parts you want. Especially when you are in a foreign country like I am. These are welding cables I was able to find so it is neither color coded for positive or negative. If you have ever done any welding you will know that you can switch between electrode negative or electrode positive using the same rig. It's far more important to get properly sized cables than color coded cables if those are the only choices you have. So use what you have and know what you are doing. I have sinced added color coded heat shrink tubing or color electrical tapr for the ends to help identity but I still always test with my multimeter.
Great vid.... Please... Could you do another load test after using the battery for 2 months. New batteries will give a decent capacity.... But what's their capacity after months or years of use? Sam's club batteries degrade hugely over the first 3 months of use. Also... For transperancy.... We're you sponsored for this vid?
Thanks. LiFePO4 batteries are suppose to improve in capacity after a few initial cycles. But after a couple of years I can test again. I paid for these out of my own pocket. If anything is sponsored I will always make it very clear in the video. It is a requirement by FTC rules but also I think it is the right thing to do.
Is the NOCO Genius correct for LiFePO4 chemistry? From what I read those NOCO profiles are for Lithium-Ion charging and I'm wondering if that's the right voltage for LiFePO4. I'd like to find a good AC charger for a bigger DIY build.
Great respect towards you! You are such an amazing find for me :) I watched milions of videos about DIY lifepo4 battery packs, but I had never been so enthusiastic building one. You made it so simple and information! Thank you soooo much! But I would like some more Ah, as I currently have 460Ah (230Ah usable) AGM battery in my camper and I would love some more. It's only 2 months old - I hope I will be able to sell it :) I know 280Ah Lifepo is a step up, but as I have a lot of extra space in my electric cabinet (2x230Ah AGM) I would put some more than 280Ah of LiFePo. But I searched a lot, but over 280Ah, there is not any items for those cheap prices. Yours 280Ah - cca 400usd 300Ah+ - 700 usd+ My question is - can I combine in 8S 8x200Ah to get 400Ah BUT still 12V!! 4 in parallel and 4 in series? Is that possible?
Thank you. Yes you can use 8 cells that are 200ah each and get 400ah 12v. You have 2 choices. Either build them as 2 separate 4s batteries and then combine them in parallel. You would need a BMS for each pack. That's callee 4S2P. Or you can build 4 sets of 2 cells each in parallel and then combine the 4 pairs of parallel cells in series. That would be a 2P4S setup. You would only need 1 BMS for that. I think the first configuration would be better at keeping the cells balanced as you would have voltage sensing and balancing for each individual cell. The second configuration you are relying on each pairs or 2p cells to keep themselves balanced as your sensing wires will be reading the each parallel pair's combined voltage. Hope that makes sense.
@@freelyroaming You man really know what you are talking :) And you make it so simple. I can totally understand what you mean. But after some consideration, I think 280Ah will be totally find for now. I can always add another pack later. PS: I am from Slovenia, full time vanlifer, but currently on Sardinia. I am not in a rush with delivery, but where did you order batteries from? From China to Croatia? And you paid cc 400€ with free shipping? What about customs and import fees? As I am looking on Aliexpress and sellers with EU supply have much higher prices - 700€, but no customs charges.
I ended up paying around $600 USD for my set of batteries including vat and customs to Croatia. Would have been cheaper if I was in the US from other sellers but Croatia is a difficult place to order stuff online. This is the seller I used. www.aliexpress.com/item/4000947956694.html
@@freelyroaming Amazing! I am wild camping all the time without any issues. The police came by very often - even on such remote places which I thought no one knows except park4night :) But they just came and turn away, as I'm not violating any laws. I am NOT camping (nothing outside of the camper). I am always inside my camper. Whenever I am out, I am doing some sport. So no problems at all. Drinking water is widely accessible for free. Fountains everywhere. Only electricity is not so easy to get from the sun this time, as I consume it a lot - only computers need 120Ah+ daily... But due to covid, all the campsites and everything touristically is closed, so shore power is an illusion :) But with tilted 400W on the roof, I get enough Ah. The toilet I have compostable which means, I don't need any service at all. Despite water and diesel :) I am here for 2 months already and will move to Sicily when it becomes a yellow zone. Don't want to risk because now Sicily is an orange zone and can easily become a red zone which means total lockdown. No thanks :)
the bms will protect it and those batteries will outlast you even if you use full capacity as i do mine..... like you say,,, cheaper than agm you expect to last a few years so you might as well thrash em !!!!!!
@@freelyroaming lol you ll never need all that power and you can't freeze them out as your charger is less than the 28a below 10% caoacity they can happily be charged in cold temps.
Hello! I am going to purchase 4pcs of DIY Lifepo4 batteries for DC12v. Its capacity will be for the time being 200-300ah. I appreciate if you would give me the battery at Alibaba Express, which you can recommend through your enough experiences. Thanks in advance for your advice.
Thank you! I have 350 watts on the roof and a portable 100 watt suitcase if necessary. This time of year in my current part of the world it is a bit difficult to get enough charge. Making my roof solar mounts tiltable has made a big difference.
@@freelyroaming thanks. I ordered 2 100 watt HQST panels and tiltable mounts yesterday. Prolly build a battery like yours, am hoping solar will be enough. Pre installed wiring from roof of RV rated for 30 amps, I'll add more panels as needed. Never saw video with summary of total battery cost, finish that one yet?
@@freelyroaming I also have Jackery 300 and 100 watt folding panel, was trying to figure how to add that without a second charge controller but prolly can't
Did you decide on a good BMS? I have 4 of these coming, but cannot get good info on BMS - especially with temp sensing below freezing that actually works.
Having 5 years experience with lithium in my RV and living in it full time, I have a bit of a problem with your design. The problem is how do you cool the cells on a hot summer day? Especially if the sun shines on the door to your battery compartment. I have found that its easy to have the battery get over 100 F or 40 C and not be able to cool down at night. I now have my compartment insulated and the cells spaced apart so air can flow through with a fan. I'm considering a liquid cooling system on my next battery build.
Wouldn't this be a problem with any battery? Why do you say it is specific to my design? most commercially available batteries do not have any active cooling. And they are completely enclosed on all sides. I have the victron battery sense installed and i will be monitoring the temperature in all environments. The battery is located inside of our insulated van. We have been living full time on the road for 13 years. If it is over 100F inside the van, we are out of there. As you know, full time traveling means following the weather. Although we have been stuck in places during heat waves, it does not happen often.
@@freelyroaming I have found that LFP produce considerable heat while charging and that heat needs to be removed. These larger 280ah cells have a lot of mass and will be harder to cool than my 100ah cells. With cells stacked right together they can eventually overheat. Lead acid batteries are much more tolerant to high temps than lithium. Remember the success of Tesla cars has much to do with their active liquid cooling of their batteries.
What C rate are you charging at? There is practically no detectable rise in heat when charged at 0.2C which is the fastest I'm able to charge with all of my charging method combined. 99% of the time they will charge at 0.1C or less. These batteries will not generate any noticeable heat in their entire lives while charging. Tesla uses different lithium chemistry and charges at massively higher C rates. Mine is a 3.6kwh battery pack that takes 8 hours to charge. Teslas can charge a 85kwh pack in 75 minutes. That is a rate of more than 150 time faster. Even when factor in their voltage differences, we are still talking about orders of magnitude differences in charging currents. These batteries should never be compared.
If you are getting a lot of heat then you could have high resistance issues somewhere in your system. Too thin of wires or terminals that aren't torqued down properly for a clean conductive surface. You might want to go over it all again to check your system.
Hi, good video, I want to build something similar for the 12V supply in my shed. I have a wind turbine with mppt charging built in. Do you think there is any reason why that might not be suitable for this kind of battery? The wind velocity here varies a lot. Gusting up to gale force is not uncommon. But the turbine has aerodynamic limiting and a voltage sensor. Even so the lead acid battery I have now has got a bit warm on windy days.
I got just over 3,600 watt hours so it will run a 200-watt load for about 18 hours assuming minimal loss of efficiency. That means having sufficiently sized wires and a high quality inverter if your load is AC. That was pretty accurate to what I got in the test.
I have a 25amp ctek battery charger, air x wind turbine, solar panel controllers the engine alternator these are all for lead acid . If I want to go lithium do I really need get rid of these no way. I wish there would be a bms that has an ability to adapt to older technology.
Only the wind turbine can be adjusted from 12-17v. Ctek charges all the way to 15v the supply mode charges up to 13,7-14.1 depending on the temperature. solar panel controllers charge up to 14,7 max same for the engine
Charging a 280Ah pack at 7 amps, empty to full in 40 hours (if it could charge full rate the entire time, which it won't, and 7.2 is a bit higher than 7). How long did it take?
The cells ships at 3.2v which is around half capacity so the first l initial charge was pretty much a full day. After the capacity test I charged it back up and it took 2 overnights plus the full day in between. I didn't really time it exactly but it was around 2 full days.
Cannot find the exact supplier you used at the price you have quoted, are you able to provide the exact seller link please? Link in description is a generic search for cells of this type, none of which are at the price point you listed.
Since this video was uploaded there has been a big increase in demand and many of the sellers are now backordered or have raised their price. You can wait for supply to catch up to demand or just pay more to get them now. Make sure you pick a seller with good feedback who is selling grade A cells. It makes a big difference.
What is the reading on this battery when it is fully charged? I know lead acid fully charged is 12.7. But what about lithium? The fullest I can charge my lithium with panels is 13.1 volts. Can you charge your battery past 13.1 with solar panels? Maybe I need more panels. Can I use a plug in charger to top my battery off more?
My solar panels have an open voltage of 22 volts. With my mppt controller I can charge these up to 14.4v which is considered full cell capacity. Once it reaches that, it will settle to around 13.7v shortly after the charger stops. My noco genius g7200 charger that plugs into AC power has a lithium mode that will bring it to 14.2 volts.
Dacian @Electrodacus has a excellent Solar battery management system that has all the features ie charging,monitoring,balancing,temperature,data logging,WiFi connectivity etc all in one.It’s an amazing piece of electronics,really genius,you don’t need all those wires.
Electrodacus also need sensing wires to each positive post of every cell for monitoring cell level voltage. He can not produce quantities in high volume therefore isn't really a product that can be practically recommended as most people won't be able to acquire one for their build. But if the Romanian team succeeds in crowdfunding their licensed clone then it could bring it into the conversation. Though even then, it is still a product for enthusiasts who knows what they are doing versus beginners that might want to try their hands on assembling their first battery.
Depends on the BMS you are using. Most of them will turn on automatically once it receives enough charging voltage. Others might require manual intervention. The Daly BMS sometime need to be manually reset by bridging the P- and B- terminals. They cut off to protect cells from being over discharged.
I was also wondering I'm going full-time in 3 years does it matter if I build one battery then next year another battery and a year after a third battery.I won't be using them until it's time to go.
@@freelyroaming Ok, But Couldn't You Put A Fire Proof Material Inside Lining The Box? Thank You For Responding So Quickly. Best Wishes, Wayne Redmond, Washington
@@freelyroaming Ok, I Know Nothing On This Subject, I Hear This Problem Of Fire With The Airlines And Tesla Auto's?? You People Know More Than I About It? My Theory Is A Common Sense One...
@wwvette LiFePO4 chemistry is not the same type of batteries that is at risk of thermal runaway like in cars. It can still short out and cause fires for sure but it's safe in comparison.
Be careful with that "capacity controller" It gets all power from cell 1. Since you have the active balancers it might be ok but I killed a cell not realizing they only draw power from the 1st cell.
Good point. I don't actually trust it too much after seeing that it doesn't automatically refresh without toggling thru the cells. I think it will be mounted but stay unplugged until I need to see cell balance data. Although it draws so little power, I'm guessing it would take many months plugged in for it to see any noticeable power consumption.
If your goal is to have one large battery then you should pair your 8 cells to 4 sets of 2 parallel cells before connecting them in series for 1 560Ah bank.
Why only a 12A load? The cells can handle a maximum of 1C discharge rate and the components I chose can do 120A constant. I will never use that much. It will probably top out at 30-50A for what I will be using them for. That's fans, lights, fridge and charging devices over USB. When you say DC-AC converter do you mean an inverter? It is a 1,000 watt pure sine inverter that will only be used to charge my laptop which draws about 150 watts. Everything else will run off of DC directly. How the van's electrical system is configured will be in a separate upcoming video. These videos are just for the battery.
Ok I see. You edited your comment from 12A to 18A so I assume you are referring to the current draw in my capacity test. That is just for a capacity test of the battery. It has nothing to do with how it will actually be used. Its purpose is to determine whether the cells will deliver the specs from the manufacturer. If you look at the discharge chart by c rate in the specs, it should achieve roughly 280Ah when discharged at a constant 0.1C rate. That is a 28A constant draw. The capacity test is to prove those specs are right and these cells pass the test.
If you are talking about the inverter used in the capacity test then it's a 300 watt inverter. But that is irrelevant because the amp draw measured is upstream from the inverter from the shunt which is measuring directly at the negative battery terminal. Or rather the load negative terminal of the BMS.
Ok. Thanks. So you plan to use a 1kw DC to AC inverter in the RV from your 12vdc lifepo4 battery pack. When each cell gets down to 2.8vdc you will be drawing roughly 90Amps (max) from the battery pack. How long can this pack deliver this amount of power? A calculation would suggest you should get about 3 hours run time when using the full 1kw AC power output (roughly 0.3C discharge rate). Have you tested and validated this?
No I will not be doing a 0.3C discharge test. As long as this passed the 0.1C rate test, I have no reason to believe a 0.3C rate test is necessary. I don't know what you mean by the 2.8v per cell statement. The cell is very close to fully depleted at that point.
Hi ! Thanks for the video. As I only have 400 W of solar panel I was thinking building a 180 ah LiFePo4 Battery (because I thought I wouldnt have enough solar power to charge a 280 ah). What do you think of that? Should I still go with a 280 ah as you do ? Because my problem is that I can't find a BMS 4S 200a that could be shipped to Europe. ... I would really appreciate your help :)
I only have 350 watts of solar and yes it isn't enough if you think you would use a full cycle every day. I do not use that much power so it is ok for me. The most I consume is about 100Ah per day. The extra capacity is insurance for those long stretches of cloudy days. And you don't need a BMS to match your battery capacity. The output is the max amount of current it will be limited in drawing. I never draw more than 75 amps at any given time so a 120A BMS works for me.
@@freelyroaming I also have been estimating that I would be consuming 100a per day. However I was afraid that somehow, I would be consuming more one day and that I would never be able to fully charge the battery again ... I need to think of that... Sorry but I didn't understand what you meant by "The output is the max amount of current it will be limited in drawing.". Does it mean that you can't consume more than 120a on your battery ? The BMS is blocking your consumption ?
It means your BMS will be limited at a max current draw of 120A. That is not the same as having a max capacity of 120Ah. You will still be able to draw the full capacity of your battery. Just not faster than 120A constant draw. That is about 1500 watts which is quite a bit of current draw. You would likely only use that much if you are running items like hair dryers, induction stoves.
@@freelyroaming Ok I was confused because I didn't know the meaning of "current draw". Thank you so much, it is so much clearer for me now :) So I guess I will go for a 120a :) And probably a 280ah if I can find one that is not shipped in 2 months !
I just put together the same system you recommended with a 250A smart-BMS with bluetooth. All cells (4x280ah) were bottom and top balanced (per Will P.) recommendation. Individual cells were top out at 3.6v in parallel then ensembled together in series with BMS. Prior to charging, all cells were balanced to around 3.337v - 3.410v. Once I started the low amp (5amps) charge, one of the cell was starting to gain in voltage faster than the other 3 cells rapidly (within 20min). I was able to monitor this via bluetooth in realtime to see the voltage gain across all 4 cells. Smart-BMS kicked in around 3.65v for the upper limit fault condition of the defective cell. It started to balance out the rest of the cells; however, its total voltage hit the upper limit as well for the Renogy charger. So the rest of the 3 good cells were topped out around 3.4v. Total Ah was around 250ah due to the defective cell (280Ah advertised). I am currently working with the vendor to replace the defective cell. Not sure how it will turn out but at least they have accepted the results that I provided. it definitely worth $ to invest in a smart BMS (even a 20A model) just to make sure you have good cells prior to install it permanently. Will P. has some good recommendation. I am currently working out some installation bugs (bluetooth and connections) with the BMS provider (may even request to refund or exchange). The technical support level from these manufacturers are non-existence. YOU ARE ON YOUR OWN.
Dan! I'm pumped that you actually got 282.4AH out of your 'cheap Chinese' batteries!!! Yay for us! Now, I'm not afraid that I'm gonna over charge or over-discharge them (I'm using (2) either @ 12v or 24v) and can't ever see a reason why I'll ever need more than 280AH draw- all at once. BUT, I notice that the AL cases seem to bow out a lil on the face? You built a box, but, I need to strap them, or, tape them to hold the cell together. I plan on using (4) 1" squares of double sided VHB tape used in the corners to hold the cell together- twice. After sort of 'holding them together' with the VHB tape, I'll either strap them by hand, or, tape them together. I'm a little concerned about the weight of (4) cells VHB'd & taped together, as I think each battery weighs 47 Lbs. I do NOT want to strip those teensy, tiny lil M6 bolts out of the anode and/or cathode, so, I prefer the least strain on that connection as possible.
That is exactly what I was worried about too. I had it originally taped together and connected with the bus bars that came with the cells. Then I realized that if the walls swelled in the heat of summer, the bus bars won't give it any room to flex and push away from each other. That's why I chose to add foam between each cell and make my own longer bus bars. The m6 terminals are definitely the weakest part of these otherwise great batteries.
Dan- I totally agree, and, I really like the foam insert between cells. That way you choose which length to make your buss bars, and, no matter how much stress- the M6 bolts are free. I'd prefer to have the cells tightly linked together (size & footprint), and- on genuine consideration of draws & loads, I NEVER think I'll ever get over 100 Amp draw. I'm using (2) either in 12v or probably 24v and DON'T plan on running my 11,000 BTU A/C off of it. Even the 'on-board' heating system doesn't draw that much. Croatia- talk about overcoming issues, in a small town, remotely located & yet- still able to git 'R done! Awesome work, my friend!
Thank you for the info and show and tell. That will make a heck if a battery for your sprinter van
Thanks. Over 3 years later it's still working great!
Great videos. Trust your readings from the Victron shunt. I have the BMV-712 and have been using since August 2019. I have the 500AMP shunt. Trust me when I say the calibration of your shunt is dead on the money. I have never seen a Victron shunt needing any field calibration. Good idea you have for making your battery last a life time. The 10%-90%. I use 80%-20% as my marker. Really appreciate all your hard work and your sharing of info. It's been a longtime since I have spoken to Croatia, I'm a ham radio operator. Call sign NF7T in the USA.
I agree trust the victron. Some of those cheaper "ebay/aliexpress" power meters assume 12V and don't actually measure the voltage.
From your video, you say it's reporting 157W 157/12 = 13.08A which is similar to what your victron was reporting.
I have one of those cheaper power meters and it's only really useful for current in/out (unless you have exactly 12V).
Very good video with clear explanations and humility. I will try teh same montage for my boat....best wishes from France !!!!!
Thank you Christophe.
Awesome video Dan, I like how you keep the camera steady, talk normal and don't play loud background music. After watching your video, I'm wondering if the Victron Smart Shunt is trully necessary as it seems to replicate what the Daly BMS gives you through their bluetooth app. I guess it's because you're using a Victron Charger and it integrates the monitoring through bluteooth? Having the little cell monitor is however truly useful as it provides instant visual feedback - inexpensively!... After 8 days of self balancing, my 16 paralleled cells stabilized at 3.47 V. I was tempted to recharge them back to 3.65 V, but I'm glad i watched your video as I realized it's not needed before assembling them as a 48V battery. I'll attach a Heyo bluetooth 320A BMS with 1A active balancing (Daly) to perform the discharge test as you did. I'll also set the BMS to 2.8V just like you did as I feel no need to push it down to the knee. Hopefully I'll also get close to 282 Ah too. I strongly doubt that I got true grade A cells, but it's not so important. What's important, is to maintain a close to 5 mV balancing differential between cells. However I realize that getting this close balancing is more of a BMS function than cell performance, as well as giving enough idling time for the BMS to do it's passive balancing. I'm actually getting down to 1 to 2 mV at time with the ANT BMS in spite of the fact that a couple of my cells (on my second battery) are running away. Indeed, the BMS intermittently shuts off with High cell Protect level 2 warnings every time the charger injects more power into it. i can see the voltage on those 2 cell spiking to 4.5V! Thanksfully the BMS shut the charging FETs OFF. These same 2 cells also trigger the Low level 2 cell protect cut off. So it's time to take the battery apart and test those 2 cells or perhaps text the FETs on the BMS. Wish me luck and thanks for your videos! Keep up the good work Dan.
Thank you Sir! I just bought my batteries in AliExpress and will be procuring the other parts for the build. I will be using my battery when overlanding.
Great video series. Very informative.
Thank you
Don, what a great video series!! Thanks a lot for taking the time to do it. I was checking at AliExpress an 8 batteries kit all the way from China to Puerto Rico, as it was the only option available for me, but the shipping cost was the same as the batteries'. I think I'll have to continue searching for other options. Any comment will be appreciated.
Wow that's crazy. If you click on the link for the batteries again in my description, you will see a lot of other vendors also selling them perhaps try a few different ones and see if that makes a difference.
Try Alibaba... I got mine there 8 cells 280 AH shipped to my home CT/USA $850.00
@@georgedemean2228 Do you have a link??
Honestly, I enjoyed your video, very informative, please disregard any negative comments, like you said it's a free country.. nobody is forcing anyone to watch...
I posted a comment in your other video... I see now why you went the battery sense route. Nice videos and build.
The voltage drops logarithmically as you discharge LiFePo4 cells. That’s why the voltage acts a little bit differently than what you’ve probably seen before. Great video!
Thanks! Yes lifepo4 discharge curve is very flat in the middle. That is why it's hard to determine capacity using voltage alone.
@@freelyroaming It was a really well done test. I like the box as well. Overall a very nice setup. I hope it serves you well and long into the future.
yes this is great info and seems to be the best value/AH---- i am trying to set up a backup to run my 17cf frig for 2 or 3 days during a Hurricane power outage- this looks like the answer!!!
Really nice build you did there and want to attemp the same thing....We live out in the Sonoran Desert of Arizona and when those temps get up into the mid 115 +/- I have found no tape that doesn't give out in that heat including that 3M stuff.. Screws into the wood with small washers up top should hold it in place
Best DIY Video For Home Made Power Station! 👍👍👍👍
Dan - thanks for taking the time - this is the second of your videos that I've checked out. Subscribed, and hoping you share more of our adventures!
It isn't just the knowledge you impart: I get nostalgic for the 18 months I spend living from a Toyota Landcruiser (troopy, we call them in Australia). Had just an 80w panel and single deep cycle battery back then, but it was enough to run a small Engel fridge, and keep my gadgets charged.
Quick question if I may: I'm speccing out a house solar setup for a remote island, and am very focused on longevity for the batteries in case sourcing new ones is a problem in the future.
This might sound a bit extreme, but I'm currently thinking of keeping the state of charge between 25 and 75 percent, leaving only 50% capacity to actually use. I'll double the battery bank capacity to compensate. So I was really interested in understanding your safety margin and how it compares to your 282ah result?
Sooo, the question: when the Victron shunt shows 100% SOC at the outset, does that mean 100% of the 90% maximum charge as per your longevity margin, or does it mean absolute 100%?
I imagine it means absolute 100% SOC, since your result of 282ah is already above the rated capacity of your cells? Likewise, I imagine that 0% according to the shunt corresponds to complete discharge, without including the 10% longevity margin, for the same reason?
What confused me a bit is that you did go into some interesting detail about how the low voltage cutoff for the BMS is 2.8v +-0.05v.
That seems like a generous protection margin already, so does it include the 10% buffer you mentioned you want on the low end? In which case could we consider the overall capacity of your cells to be even higher than 282ah? Are you going to be relying on the BMS for setting your custom margins (does it allow custom settings)? Or are you going to program that into the Victron shunt? Or will your charger allow custom settings?
Happy trails!
The BMS spec sheet he was looking at was for Li Ion not LiFeP04. Cells can go down to 2.5V or 2.0V, refer to spec sheet
your english is so clear.. im enjoying watching you
Excellent presentation, both the first and this one. Thanks, Freely Roaming.
Thank you! Glad you liked it.
very informative video. Thank you. Keep up the good work.
Thank you!
Great and informative series. I love the intro of all your videos.
Watching it all however made me skeptical, the amount of money and time spent and the longevity of the batteries. Is it really all that worth the hassle?
Thanks. Whether or not it's worth the hassle depends completely on the person. If you are not the DIY type then it's probably not for you. This battery will last 10+ years. I've been using it already for 2 years and there are no signs of degradation. If you just want to buy an off the shelf battery, they are available these days for a lot less than they were before. DIY will still be cheaper but the gap is narrowing.
drill some holes for battery capacitance meter and main battery leads; then use grommets.
It's your fault, I watch nobody else do energy...😂 just kidding, but Im watching a lot of your videos. Thank you!
I have 16 of these cells on their way and I have been trying to figure out the best way to mount them. I had considered using the shipping foam but I was a bit afraid of overheating the batteries under high load. That is certainly something Id be paying attention to.
The victeon battery sense is best placed in between the cells to more accurately measure the temperature of the cells when you are charging them.
The charger will then use the entered temperature coefficient value to modify the charge rate.
Temperature compensation is disabled in my Victron chargers. The battery sense is used for low temp disconnect. You can see how this has been reconfigured in my cold weather modifications series.
@@freelyroaming ah gotcha
be very careful leaving that hobby "Capacity meter" powered full time. The reason is that it pulls it's power from cell 1, meaning it will slowly drain that one cell just to "keep it's lights on" hope this helps.
Since the BMS and the active balancer are both keeping the cells in balance, the miniscule draw from cell 1 will never be an issue. It will practically instantly be balance with the other cells. All of the components I'm using all will put a small load on the pack as well. The bms, active balancer, shunt, temp sensor all run at net negative power. But it would take many months to parasitically drain this pack.
I capacity tested a small battery last night, I used a capacity meter, and 200watts of led flood lights, the house was flooded with light last night! Ha-ha, the pack came to about 20ah, my 33kwh house battery is not going to be easy to verify, ha... That's over 1k ah. I have 3400w of panels to put up also, I hope to get more battery, and more solar, and build some type of ev, even if it's only a electric tricycle! A 20"-24" trike, with 2, 5kw motors, and a 1.5-3kwh battery would be a mean macheen! I do have enough cells to build a 32ah 28s battery for a small e bike, to be charged from my off grid house power system!! So I can build a 48v, 60v, 72v or even 96v, maybe a 120vdc, and the cells are capable of a sustainable 200amps each, so 4p would be insanity for a E bike, a bit off topic, and rambling sorry!!
You've got some projects ahead of you! Good luck.
Awesome video man, thanks!
Im gonna be having this same lifepo4 build for my portable solar gen. Project.
Good choice. Make sure to source the cells from a reliable seller with grade A cells and you will be good to go.
@@freelyroaming noted sir ...thanks for the advice.
I hope so too! Good luck.
I watched your video (and subscribed) with great interest. I am a newbie to lithium. I took out two 12v AGMs replacing them with one 12v 170 Ah "Big Battery"with the Anderson connectors. I bought a Progressive Dynamics 9100AL lithium 60amp charger. What's new to the mix is the Victron Smart Shunt followed you kink. ...I'm just not sure what parameters to put in....so I copied yours I charged the battery for 24 hours it showed 14.5 V. I added all the components together on my work bench. Hooked up a 1000 inverter, plug in two 150w flood lights, clipped my Amp meter set on amps on the Positive cable into the battery and Multimeter on the Pos/neg out of the charger (just to double check) the I wired in the Smart Shunt, entered your parameters except battery amp hours. Discharged the battery until the inverter shut off at 10.5v. 169.5 amp hours showed on the connect app. When I took off the load and plugged the charger back in the connect app showed 100% SOC even though the battery and meter showed 13.2V that is 70% SOC according to the little chart you had. I manually changed the SOC to 70% and started charging again....WRONG OR RIGHT THING TO DO. In the mean time I will hang on your every word and intend to build a companion Battery when the funds allow. Keep on Keeping on. Happy New Year, Peace and Blessings, Richard
I would just charge your battery all the way up until the charger goes to float stage. Meaning there are no more amps going thru up in the charging wires. Then set the SoC in the app to 100%. That should give you a good place to start for all of your subsequent charge cycles. Just make sure that there are no loads in your system that isn't going thru the shunt so you are capturing everything.
@@freelyroaming Thank you much. I did just that.
@@freelyroaming Thanks that helps alot
realy great job !!
thx a lot
Great video I would love 3 of these packs for my off-grid setup that would like 10.8kw, awesome!
Am I right in saying that your charge input mode (Noco) should be set as a standard "flat" feed? As you already have a BMS managing the charging, as well as a balancer, there's no need for a shaped current/voltage feed like the Noco's lithium option offers. All larger retail lithium batteries I have seen, for cars, motorbikes etc. state to use a "normal" charger, because the battery already contains the BMS circuit inside. You, in effect, have the same system. Food for thought.
You can use a constant current charger for LiFePO4 with or without a BMS. The BMS doesn't affect or 'shape' charging current at all.
I've learned that when charging LiFePO4 cell it's full when voltage here to 3.6 to 3.65 volts. That means 14.5 to 14.6 volts.
When charger is stopped, voltage sets lower.
Another important value is 20% remaining charge which when lightly discharged is 12.6 volts.
I'm also tuning in my chinese battery monitor supervising GWL 12V 90Ah battery which doesn't have BMS...
Please more precise link for the batteries.ty.Big hello from MACEDONIA
Thanks Dan!!
Differences on meters can be result of voltage drop / power losses on cables that get warm/hot - too thin cable diameter.
Excellent video. Thanks
Thanks Bill!
Great videos! Do you have the LF280 or the LF280K?
Very well done. Please excuse me if I missed it but what did you end up with for a total build cost and how long did it take? Understanding that you did have some delays in sourcing. I'm more interested in working time.
Thank you Brian. So once I got all the parts the whole battery was built in an afternoon. But of course that is not counting the capacity testing time which took several days with a slow charger I had to use. The total build cost for me was around $1000. In the US you can get the same parts for about $800. In the next video I will outline them exactly for you guys.
Great stuff again! Thanks 👍
right know for testing I have my 4 280ah cells in a plastic battery box for testing. Before I really start using it I need to clamp the batteries together, otherwise I read they can swell during heavy use and rip the terminals if the buss bars will not flex. Your factory bus bars are curved, and mine are straight leaving no room for flexing if and when the packs start to swell.
What are you planning to do with your battery? When you say heavy use, what will a typical day look like for these batteries? There is the normal expansion and contraction that happens with these cells when you charge and discharge that's completely harmless. Then there is repeated constant high c-rated draw that can generate enough heat causing excessive swelling which can lead to delamination of the internals. Like extensive use of induction cooktop or powering an air conditioner. The latter is what the compression technique is suppose to prevent. Mine will never be drawn beyond 0.2C so delamination should never be a problem. So my solution is to give the cells some added room to expand and contract naturally. I ditched the factory bus bars and made my own longer ones from copper pipes. It can be as little as using double sided foam tape between each cell to connect them then wrapping the with kapton tape on the outside. Your bus bar may provide enough wiggle room to allow that extra space. Also keep in mind that most factory build packs do not compress their cells tightly together like what some people are suggesting. The ideal solution for this problem depends a lot on how the battery will be used.
BTW towards the end around the 27 min mark I see at the distance what appears to be a Mazda Rx4 wagon, too far to distinguish... I owned many of the RE engine Mazdas from the 70s. Pound for pound they are little beasts.
Unfortunately not. That is an old rusty Soviet era Russian junker 😝
Hi I've been watching your videos for past few hours, would this set up you did be ok with vibration from a car audio system?
I plan on buying 90ah version of the batteries and looking at bms from bms overkill. Is there anything I should be concerned about due vibrations. Or taking anything into consideration? I plan on have the battery next to subwoofer box. Thanks for sharing your knowledge with others!
So fluid you can almost tell he’s not even reading 😳😆😄
Nice job! I'll be doing mine in a few weeks :)
Thanks! Good luck!
Wow this seems a lot different devices
@8:36 you need to change the Peukert Exponent to 1.00 or 1.01 (It might not support 1.00). You have it set at 1.25 now which is for lead acids under high loads. The Peukert effect isn't applicable for LifePO4 batteries.
You will see in part 4 when I installed and programmed all the chargers in the camper is when I updated the Victron settings including setting the peukert constant. What you see in here are the defaults that came with the SmartShunt.
It's been a couple months now so when each step was done is getting a little fuzzy in my memory. But yes I understand peukerts law and how it effects the different battery types. Someone else has mentioned it before I installed it into the camper.
Hi, me again... Im all in to make a batyery bank for home use. My question is how many batteries cells can I parallel? I see you use 4 to make a 280A system, can I safely string more, or what would be a good fit for a home minus electric stove. Im still learning the math portion. Thank you Dan good day.😊
I'm assuming the Ah rating of your lithium batteries are a 20 hour rate. That means in order to truly test their capacity you'll need to apply a constant 14A DC load. Your original current was lower which is why you ended up with a higher capacity result.
If you read the spec sheet you can see that a 0.1C discharge doesn't give you much more capacity than a 0.2C discharge rate. Maybe I could squeeze 2-3 Ah more out of the 280 Ah rating at a lower discharge rate. Either way, these cells pulled the rated capacity as expected.
Did you "add" the house bank to the van ? You had mentioned 4 sources of charging, no mention of charging from the vans chassis alternator itself. If my RV has been wired to charge from the chassis alternator to the house battery, is the alternator charging parameter not good for the LiFe PO4 battery pack build you have just shown ? Right now my RV has 2 of the AGM 105 ah group 29's. So your build gets 280ah vs 210 ah , but the useable is so much greater. The RV does not have a dc to dc charger yet, but I will install one. Remove the alternator wire ?
I do not charge directly from the alternator but rather a dc to dc charger instead. Charging directly from the alternator without a current regulating charger can cause potential damage to the battery as well as the alternator itself.
Yes A good vid ye Thanks again
Great video, I have one question I have a battery pack (Lithium Iron) connected to dash cam in my car. When vehicle is on the battery get recharge at 14.6V at 9 amps. It has an XT60 battery expansion port. I would like to know if I connect the above battery pack using the XT60 connector will the above battery charge and will be able to discharge back to main battery ?
thanks for the great videos... and a question...
is there constantly a bluetooth signal coming from this battery box setup? or is there a way to turn it off?
It is always on. I'm not aware of a way to turn it on or off
@@freelyroaming which component in the battery box is broadcasting the bluetooth signal?
Victron Battery Sense and Victron SmartShunt
Great video. I have subscribed to your channel and look forward to learning more. What is the total weight of your assembled battery?
What's it like in Croatia? Is it easy to get the property out there?
No idea what getting property here is like. We have family land here going back a long time. I see real estate listings but have never talked to anyone about it. I do believe it is pretty expensive as compared to other Balkan countries. At least on the coast.
Hey thanks for sharing your setup, I was curious, does the position of the battery sense matter for accurately measuring the temperature you set for your low temp disconnect? Or is any mounting position fine as long as its close to the batteries?
great videos thanks so much, love it
Great video! Love it.. been using your vids to do something similar.. but do you know the recommended charge rate for the battery pack? I ended up with an expanded cell with using a 30a charge rate so that will be replaced.. but thinking it would be required to have the charge rate of the pack be aligned with the cell balancer.. if that's out of what, then would not one cell be charged more than the others or something to that nature?
30A charge rate is no where near the limit for these cells. I suspect there were other problems already existing that caused the expansion.
also, the discrepancy that you are seeing comes from the fact that most meters don't include their OWN consumption, so depending where the meters are they include different things
As you might have seen from the video, there was never any discrepancy. what I saw was due to the refresh interval of the hobby capacity controller. It has a delay in the reading and is refreshed when the buttons are pressed. The reading are actually exactly the same. The amount of power consumption is really insignificant with a battery this size. It may matter with a small lipo cell but with this 3,600Wh pack, their consumption is virtually undetectable. We're talking sub-microvolt differences that none of my instruments are capable of reading.
Hey great video it doesn’t say in the aliexpress ad but can you tell me how tall those cells are?
Dan, GREAT VIDEOS! You're inspiring me to build my own also. I don't have time to read all the comments below, and I'm thinking that my question may be answered already. Just curious about getting all the other items besides the BMS and the cells. How many of them are necessary?
air flow would be a good thing in that box...
thanks
thanks
Am I the only one concerned that he's using cables that are color-coded as ground for power? Because that seems potentially dangerous. Otherwise very interesting; I expect I'll be using some similar cells soon, though in a different application.
Always test with a multimeter for polarity even if the cables are color coded. With DIY projects, you can't always get the parts you want. Especially when you are in a foreign country like I am. These are welding cables I was able to find so it is neither color coded for positive or negative. If you have ever done any welding you will know that you can switch between electrode negative or electrode positive using the same rig. It's far more important to get properly sized cables than color coded cables if those are the only choices you have. So use what you have and know what you are doing. I have sinced added color coded heat shrink tubing or color electrical tapr for the ends to help identity but I still always test with my multimeter.
Great vid.... Please... Could you do another load test after using the battery for 2 months. New batteries will give a decent capacity.... But what's their capacity after months or years of use?
Sam's club batteries degrade hugely over the first 3 months of use.
Also... For transperancy.... We're you sponsored for this vid?
Thanks. LiFePO4 batteries are suppose to improve in capacity after a few initial cycles. But after a couple of years I can test again. I paid for these out of my own pocket. If anything is sponsored I will always make it very clear in the video. It is a requirement by FTC rules but also I think it is the right thing to do.
@@freelyroaming... Thank you. It is very difficult to find real.... DIY people who give good, proven information.
What size is the genius charger...
What size solar are you charging with..??
Thanks for another great video!
Is the NOCO Genius correct for LiFePO4 chemistry? From what I read those NOCO profiles are for Lithium-Ion charging and I'm wondering if that's the right voltage for LiFePO4. I'd like to find a good AC charger for a bigger DIY build.
Yes they are LiFePO4 compatible.
Great respect towards you! You are such an amazing find for me :)
I watched milions of videos about DIY lifepo4 battery packs, but I had never been so enthusiastic building one. You made it so simple and information! Thank you soooo much!
But I would like some more Ah, as I currently have 460Ah (230Ah usable) AGM battery in my camper and I would love some more. It's only 2 months old - I hope I will be able to sell it :)
I know 280Ah Lifepo is a step up, but as I have a lot of extra space in my electric cabinet (2x230Ah AGM) I would put some more than 280Ah of LiFePo. But I searched a lot, but over 280Ah, there is not any items for those cheap prices.
Yours 280Ah - cca 400usd
300Ah+ - 700 usd+
My question is - can I combine in 8S 8x200Ah
to get 400Ah BUT still 12V!!
4 in parallel and 4 in series?
Is that possible?
Thank you. Yes you can use 8 cells that are 200ah each and get 400ah 12v. You have 2 choices. Either build them as 2 separate 4s batteries and then combine them in parallel. You would need a BMS for each pack. That's callee 4S2P. Or you can build 4 sets of 2 cells each in parallel and then combine the 4 pairs of parallel cells in series. That would be a 2P4S setup. You would only need 1 BMS for that. I think the first configuration would be better at keeping the cells balanced as you would have voltage sensing and balancing for each individual cell. The second configuration you are relying on each pairs or 2p cells to keep themselves balanced as your sensing wires will be reading the each parallel pair's combined voltage. Hope that makes sense.
@@freelyroaming You man really know what you are talking :) And you make it so simple. I can totally understand what you mean. But after some consideration, I think 280Ah will be totally find for now. I can always add another pack later.
PS: I am from Slovenia, full time vanlifer, but currently on Sardinia. I am not in a rush with delivery, but where did you order batteries from? From China to Croatia? And you paid cc 400€ with free shipping? What about customs and import fees?
As I am looking on Aliexpress and sellers with EU supply have much higher prices - 700€, but no customs charges.
I ended up paying around $600 USD for my set of batteries including vat and customs to Croatia. Would have been cheaper if I was in the US from other sellers but Croatia is a difficult place to order stuff online. This is the seller I used.
www.aliexpress.com/item/4000947956694.html
How is it in Sardignia? Any issues with finding places to camp?
@@freelyroaming Amazing! I am wild camping all the time without any issues. The police came by very often - even on such remote places which I thought no one knows except park4night :) But they just came and turn away, as I'm not violating any laws. I am NOT camping (nothing outside of the camper). I am always inside my camper. Whenever I am out, I am doing some sport. So no problems at all.
Drinking water is widely accessible for free. Fountains everywhere.
Only electricity is not so easy to get from the sun this time, as I consume it a lot - only computers need 120Ah+ daily...
But due to covid, all the campsites and everything touristically is closed, so shore power is an illusion :) But with tilted 400W on the roof, I get enough Ah.
The toilet I have compostable which means, I don't need any service at all. Despite water and diesel :)
I am here for 2 months already and will move to Sicily when it becomes a yellow zone. Don't want to risk because now Sicily is an orange zone and can easily become a red zone which means total lockdown. No thanks :)
the bms will protect it and those batteries will outlast you even if you use full capacity as i do mine.....
like you say,,,
cheaper than agm you expect to last a few years so you might as well thrash em !!!!!!
Haha well time will tell how I end up treating these cells. We've got some cold weather coming so hopefully I don't freeze them out.
@@freelyroaming lol you ll never need all that power and you can't freeze them out as your charger is less than the 28a below 10% caoacity they can happily be charged in cold temps.
Hello! I am going to purchase 4pcs of DIY Lifepo4 batteries for DC12v. Its capacity will be for the time being 200-300ah. I appreciate if you would give me the battery at Alibaba Express, which you can recommend through your enough experiences. Thanks in advance for your advice.
Awesome!
Great series! How much wattage in panels on roof of van to charge it?
Thank you! I have 350 watts on the roof and a portable 100 watt suitcase if necessary. This time of year in my current part of the world it is a bit difficult to get enough charge. Making my roof solar mounts tiltable has made a big difference.
@@freelyroaming thanks. I ordered 2 100 watt HQST panels and tiltable mounts yesterday.
Prolly build a battery like yours, am hoping solar will be enough. Pre installed wiring from roof of RV rated for 30 amps, I'll add more panels as needed. Never saw video with summary of total battery cost, finish that one yet?
@@freelyroaming I also have Jackery 300 and 100 watt folding panel, was trying to figure how to add that without a second charge controller but prolly can't
These batteries went from $390 to $517 in two weeks?
I not buy this... When good reviews they jump the price. So not good ... :) The price are hilarious
Did you decide on a good BMS? I have 4 of these coming, but cannot get good info on BMS - especially with temp sensing below freezing that actually works.
Look up Overkill BMS. I have heard good things.
How much Maximum Amp charger we can use with this package to charge fast as much we can?
So, that pack of four gives 4*3.2*280 = 3 584
In usual car batterie numbers its around 3,5 kwh for 500$ ?
Saw a peukert setting at 1.25, which isn't correct, it should be 1.02 for lipo4
It has been set at 1.00 since it was installed.
Hello Don , how many hours the bulbs burning in total , good info
It ran for about 19 hours at around 200 watts
that BMS didn't really work?
Having 5 years experience with lithium in my RV and living in it full time, I have a bit of a problem with your design. The problem is how do you cool the cells on a hot summer day? Especially if the sun shines on the door to your battery compartment. I have found that its easy to have the battery get over 100 F or 40 C and not be able to cool down at night. I now have my compartment insulated and the cells spaced apart so air can flow through with a fan.
I'm considering a liquid cooling system on my next battery build.
Wouldn't this be a problem with any battery? Why do you say it is specific to my design? most commercially available batteries do not have any active cooling. And they are completely enclosed on all sides. I have the victron battery sense installed and i will be monitoring the temperature in all environments. The battery is located inside of our insulated van. We have been living full time on the road for 13 years. If it is over 100F inside the van, we are out of there. As you know, full time traveling means following the weather. Although we have been stuck in places during heat waves, it does not happen often.
@@freelyroaming I have found that LFP produce considerable heat while charging and that heat needs to be removed. These larger 280ah cells have a lot of mass and will be harder to cool than my 100ah cells. With cells stacked right together they can eventually overheat. Lead acid batteries are much more tolerant to high temps than lithium. Remember the success of Tesla cars has much to do with their active liquid cooling of their batteries.
Its true, i usually run a 2 watt fan for all electronics. Cross ventilation
What C rate are you charging at? There is practically no detectable rise in heat when charged at 0.2C which is the fastest I'm able to charge with all of my charging method combined. 99% of the time they will charge at 0.1C or less. These batteries will not generate any noticeable heat in their entire lives while charging. Tesla uses different lithium chemistry and charges at massively higher C rates. Mine is a 3.6kwh battery pack that takes 8 hours to charge. Teslas can charge a 85kwh pack in 75 minutes. That is a rate of more than 150 time faster. Even when factor in their voltage differences, we are still talking about orders of magnitude differences in charging currents. These batteries should never be compared.
If you are getting a lot of heat then you could have high resistance issues somewhere in your system. Too thin of wires or terminals that aren't torqued down properly for a clean conductive surface. You might want to go over it all again to check your system.
Hi, good video, I want to build something similar for the 12V supply in my shed. I have a wind turbine with mppt charging built in. Do you think there is any reason why that might not be suitable for this kind of battery? The wind velocity here varies a lot. Gusting up to gale force is not uncommon. But the turbine has aerodynamic limiting and a voltage sensor. Even so the lead acid battery I have now has got a bit warm on windy days.
As long as your mppt controller is compatible with LiFePO4 batteries then you should be fine.
awesome
Did I miss where you said how many hours you got at 200w output?
I got just over 3,600 watt hours so it will run a 200-watt load for about 18 hours assuming minimal loss of efficiency. That means having sufficiently sized wires and a high quality inverter if your load is AC. That was pretty accurate to what I got in the test.
@@freelyroaming thank you, I have a similarly sized battery and was wondering approximately how long I would be able to power my freezer at 130w
I have a 25amp ctek battery charger, air x wind turbine, solar panel controllers the engine alternator these are all for lead acid . If I want to go lithium do I really need get rid of these no way. I wish there would be a bms that has an ability to adapt to older technology.
Only the wind turbine can be adjusted from 12-17v. Ctek charges all the way to 15v the supply mode charges up to 13,7-14.1 depending on the temperature. solar panel controllers charge up to 14,7 max same for the engine
Balance Plug's for charging the battery. I couldn't recharge my Helicopter's without them.
What about the link for the batteries 🤠🤠🤠.I want to buy also.ty
Charging a 280Ah pack at 7 amps, empty to full in 40 hours (if it could charge full rate the entire time, which it won't, and 7.2 is a bit higher than 7). How long did it take?
The cells ships at 3.2v which is around half capacity so the first l initial charge was pretty much a full day. After the capacity test I charged it back up and it took 2 overnights plus the full day in between. I didn't really time it exactly but it was around 2 full days.
Cannot find the exact supplier you used at the price you have quoted, are you able to provide the exact seller link please? Link in description is a generic search for cells of this type, none of which are at the price point you listed.
Since this video was uploaded there has been a big increase in demand and many of the sellers are now backordered or have raised their price. You can wait for supply to catch up to demand or just pay more to get them now. Make sure you pick a seller with good feedback who is selling grade A cells. It makes a big difference.
@@freelyroaming thank you, will do. I Appreciate the assistance
What is the reading on this battery when it is fully charged? I know lead acid fully charged is 12.7. But what about lithium? The fullest I can charge my lithium with panels is 13.1 volts. Can you charge your battery past 13.1 with solar panels? Maybe I need more panels. Can I use a plug in charger to top my battery off more?
My solar panels have an open voltage of 22 volts. With my mppt controller I can charge these up to 14.4v which is considered full cell capacity. Once it reaches that, it will settle to around 13.7v shortly after the charger stops. My noco genius g7200 charger that plugs into AC power has a lithium mode that will bring it to 14.2 volts.
@@freelyroaming thanks. If I add more solar panels will my battery charge faster?
Dacian @Electrodacus has a excellent Solar battery management system that has all the features ie charging,monitoring,balancing,temperature,data logging,WiFi connectivity etc all in one.It’s an amazing piece of electronics,really genius,you don’t need all those wires.
Electrodacus also need sensing wires to each positive post of every cell for monitoring cell level voltage. He can not produce quantities in high volume therefore isn't really a product that can be practically recommended as most people won't be able to acquire one for their build. But if the Romanian team succeeds in crowdfunding their licensed clone then it could bring it into the conversation. Though even then, it is still a product for enthusiasts who knows what they are doing versus beginners that might want to try their hands on assembling their first battery.
how much did this cost all together
If the BMS did cut off from low voltage, do you nwed to reset it? If yes, why and how?
Depends on the BMS you are using. Most of them will turn on automatically once it receives enough charging voltage. Others might require manual intervention. The Daly BMS sometime need to be manually reset by bridging the P- and B- terminals. They cut off to protect cells from being over discharged.
I was also wondering I'm going full-time in 3 years does it matter if I build one battery then next year another battery and a year after a third battery.I won't be using them until it's time to go.
I think it would be best to buy all your batteries at the same time. That way you know they are matched and of the same age.
Shouldn't You Use A Metal Box?
Just Thinking Of Fire Danger?
Metal can cause dead shorts and is more likely to cause a fire.
@@freelyroaming Ok,
But Couldn't You Put A Fire Proof Material Inside Lining The Box?
Thank You For Responding So Quickly.
Best Wishes,
Wayne
Redmond, Washington
@@wwvette it's a lot more complicated to use metal and it doesn't really offer any real advantages.
@@freelyroaming Ok, I Know Nothing On This Subject, I Hear This Problem Of Fire With The Airlines And Tesla Auto's??
You People Know More Than I About It?
My Theory Is A Common Sense One...
@wwvette LiFePO4 chemistry is not the same type of batteries that is at risk of thermal runaway like in cars. It can still short out and cause fires for sure but it's safe in comparison.
Be careful with that "capacity controller" It gets all power from cell 1. Since you have the active balancers it might be ok but I killed a cell not realizing they only draw power from the 1st cell.
Good point. I don't actually trust it too much after seeing that it doesn't automatically refresh without toggling thru the cells. I think it will be mounted but stay unplugged until I need to see cell balance data. Although it draws so little power, I'm guessing it would take many months plugged in for it to see any noticeable power consumption.
I didn’t quite understood how much did you pay for the shunt?
The link to the shunt is in the description
so if I have 8 of those and make two 12 volt batteries they should give me 560ish amp hours. Is that correct?
If your goal is to have one large battery then you should pair your 8 cells to 4 sets of 2 parallel cells before connecting them in series for 1 560Ah bank.
@@freelyroaming My goal is to be able to watch tv at night charge 2 phones and one laptop maybe Playststion and then charge during the day
So you only plan to use a 18 Amp load in your RV with these batteries? What size DC to AC converter did you use?
Why only a 12A load? The cells can handle a maximum of 1C discharge rate and the components I chose can do 120A constant. I will never use that much. It will probably top out at 30-50A for what I will be using them for. That's fans, lights, fridge and charging devices over USB. When you say DC-AC converter do you mean an inverter? It is a 1,000 watt pure sine inverter that will only be used to charge my laptop which draws about 150 watts. Everything else will run off of DC directly. How the van's electrical system is configured will be in a separate upcoming video. These videos are just for the battery.
Ok I see. You edited your comment from 12A to 18A so I assume you are referring to the current draw in my capacity test. That is just for a capacity test of the battery. It has nothing to do with how it will actually be used. Its purpose is to determine whether the cells will deliver the specs from the manufacturer. If you look at the discharge chart by c rate in the specs, it should achieve roughly 280Ah when discharged at a constant 0.1C rate. That is a 28A constant draw. The capacity test is to prove those specs are right and these cells pass the test.
If you are talking about the inverter used in the capacity test then it's a 300 watt inverter. But that is irrelevant because the amp draw measured is upstream from the inverter from the shunt which is measuring directly at the negative battery terminal. Or rather the load negative terminal of the BMS.
Ok. Thanks. So you plan to use a 1kw DC to AC inverter in the RV from your 12vdc lifepo4 battery pack. When each cell gets down to 2.8vdc you will be drawing roughly 90Amps (max) from the battery pack. How long can this pack deliver this amount of power? A calculation would suggest you should get about 3 hours run time when using the full 1kw AC power output (roughly 0.3C discharge rate). Have you tested and validated this?
No I will not be doing a 0.3C discharge test. As long as this passed the 0.1C rate test, I have no reason to believe a 0.3C rate test is necessary. I don't know what you mean by the 2.8v per cell statement. The cell is very close to fully depleted at that point.
Hi ! Thanks for the video. As I only have 400 W of solar panel I was thinking building a 180 ah LiFePo4 Battery (because I thought I wouldnt have enough solar power to charge a 280 ah). What do you think of that? Should I still go with a 280 ah as you do ? Because my problem is that I can't find a BMS 4S 200a that could be shipped to Europe. ... I would really appreciate your help :)
Oh but wait... you are using a 120a BMS with a 280ah battery ? How is that possible ?
I only have 350 watts of solar and yes it isn't enough if you think you would use a full cycle every day. I do not use that much power so it is ok for me. The most I consume is about 100Ah per day. The extra capacity is insurance for those long stretches of cloudy days. And you don't need a BMS to match your battery capacity. The output is the max amount of current it will be limited in drawing. I never draw more than 75 amps at any given time so a 120A BMS works for me.
@@freelyroaming I also have been estimating that I would be consuming 100a per day. However I was afraid that somehow, I would be consuming more one day and that I would never be able to fully charge the battery again ... I need to think of that...
Sorry but I didn't understand what you meant by "The output is the max amount of current it will be limited in drawing.". Does it mean that you can't consume more than 120a on your battery ? The BMS is blocking your consumption ?
It means your BMS will be limited at a max current draw of 120A. That is not the same as having a max capacity of 120Ah. You will still be able to draw the full capacity of your battery. Just not faster than 120A constant draw. That is about 1500 watts which is quite a bit of current draw. You would likely only use that much if you are running items like hair dryers, induction stoves.
@@freelyroaming Ok I was confused because I didn't know the meaning of "current draw". Thank you so much, it is so much clearer for me now :) So I guess I will go for a 120a :) And probably a 280ah if I can find one that is not shipped in 2 months !