First, THANK YOU VERY MUCH for taking the time, spending the money & doing all of the 'heavy lifting' of testing these cells (that I was sooo excited about!) I'm more than a little disappointed that the cells varied by so much? Clearly, 2 cells came from a single batch, and the other (2) came from another. They varied enough that I wondered if 2 of the cells were from say 'version A' and the other 2 came from a more recent & improved lot. That being said: * I probably would've used a lower gauge wire to reduce losses (say 6 AWG or even a 4 AWG)? * I may've tried to do a .2C test, but- really I'm being a nitpicker, and, the wiring mentioned above would've been less of an issue, but... * I thought each cell was limited to 2.5v, so I was surprised to see 2.2v as the bottom? Asking? * Would it have helped to parallel the cells for a day or so- for the BMS & preventing the need for a bottom balance? * Do you think it might've performed slightly better (275 -280AH) if you had bottom balanced? Great test, great review & THANK YOU 1,000 times!!! I genuinely appreciate your efforts. Noted: another gentleman purchased 16 cells for a garage solar power project and he only was able to get @ 250AH or so. Perhaps they are slightly less powerful and they DO have limitations (none that will disturb me using them..) But, they still have a TON of stored power & the chemistry lasts for so many cycles!!! Dave
Its the role of the BMS to handle balancing for you. Having the cells connected to a bms for a day should give you the same result as connecting them parallel - they should get balanced. And a BMS is safer since it wil reduce/regulate the balancing current.
* Thanks!! :) * The read/black cables coming off the battery were 4 AWG. The black cable from the shunt to the inverter was 1/0 AWG as I already had a piece with ring terminals crimped on. * One thing I find interesting about the prismatic LiFePO4 batteries I've looked at is the capacity is usually given at a 1C discharge. I find that hard to believe, but I haven't tried a 1C test to see what happens. With this in mind, I think a 0.28C test is close enough to 0.2C commonly used by NMC chemistries. Lower amps may have resulted in another Ah or two, not sure. * The spec sheet for these batteries gave 2.5V as the low cutoff. The BMS was set for 2.2V. I can't change it for this particular BMS and wanted to leave it go to see what would happen (if the BMS would shut off). The voltage drop at that point in the discharge curve is so steep that the extra between 2.228V and 2.50V didn't make much of a difference. * Yes! I do think paralleling beforehand would have helped. I will be testing this later this week to see if there is any difference. I will report back my findings. I don't think the iCharger balanced long enough even though I had it set to "slow balance".
@@LithiumSolar I hope that you understand that I'm NOT questioning you in a 'snarky' way, I'm really trying to learn more (and, I'm more of a NOOB!) while being 'clear' instead of loose. Thanks (again!!!) for buying & testing these- I so appreciate all of your efforts! I was planning on using (2) Bluetooth programmable BMS' recommended by Will Prowse & paralleling them on arrival, discharging to a lower state of charge, balancing- charge & do a .2C rate test. .28C is so darn close- it thought it was higher (my bad!) Either way, 271AH is purdy darn close & still an exceptional value. I DO wish you had received 'matched' cells by lot as well as charge profile & resistance but at that price- it may be too much to ask! Hahaha
@@hubertnnn I think that Daly BMS' only charge at the very top of the charge cycle, and, often needs several charge cycles to balance the cells. When installed, the cell voltage variance was too large for it to even work. The resistors are pretty small on most BMS' that I've ever seen. With such a flat discharge curve, the amount of voltage in each cell can be pretty large -especially in 280AH prismatic cells!
@@DCGULL01 being snarky didn't even cross my mind... Out of all the comments, yours was the one I pinned lol. I am not an expert and am here to learn too. One reason I make these videos is I love reading through the comments, ideas, hearing what others are doing, etc. I do agree, 271Ah is still fantastic - I guess I just expected to see the full 280Ah after what I've been reading from others. I'll be ordering my next batch from Basen (seems to be who most are recommending) and getting 16 at once. Hopefully those will be matched. I love the Daly BMS for small builds and testing, but I'll be using a Batrium on my final production setup :)
You got 97% of the rated capacity, and your breaker and negative cable were generating some heat. The 300 mV drop from the terminals to the shunt is also about 97% of the voltage, so the cells seem to be pretty close to 280Ah. And for that price, seems like you did well!
The losses in cables, breaker etc do not affect Ah-measurement. The shunt measures the current going through the circuit and it does not matter where the energy is dissipated, whether in the actual load or elsewhere.
@@mcg6762 Errm. No. I don't believe that is accurate. Any losses between the terminal and the shunt (which is where my comment clearly identified the 300mV loss) is dissipated as heat before it any measurment by the shunt. That 300mV X (the amps) equals power lost at any moment, and power lost over a period of time is lost energy. See the First Law of Thermodynamics--the Law of Conservation of Energy for more info.
@@daveduncan2748 Ah is different from Wh. The shunt measures current. All current must go through the shunt, regardless of where the voltage is dropped.
@@The2000redrocket If you have more than one shunt in the same series circuit they would all measure the same current. Basic circuit theory. The current is the same everywhere for a straight series circuit.
I've watched a few of these for the 280 ah and most get the 280 or close with all the wiring and such 271 seems close enough for me. You do great work thanks.
Wow! a most excellent video. Great production. Lighting, audio quality, and your narration. Just easy to watch, and appreciate your thoroughness. Going to watch more of your channel. Thank you!
I've been debating selling my 16s NMC pack and dropping $10k or so on a massive bank of these. I don't like that they don't even have the rated capacity out of the box though. Thanks for digging into them!
Not sure about your datasheet, but Off Grid Garage found that his 'manual' said to let the cells sit for an hour after charging before starting the test or something like that.
Thanks for the review. I just ordered 4 280Ah cells from an eBay seller for about $170/cell, so not as good of a deal as yours... I’m just hoping they are matched, new cells, as they were advertised! This makes such a nice, compact, high capacity battery. Even at what I paid, it will be cheaper per usable amp hour than purchasing AGM batteries (considering 80% DOD for the LiFePO4 and 50% for the AGM). Thanks again for the review/capacity test!
Many users are buying from this resller called XUBA and specifcally asking for AMY as there rep. I bought 32 all same qr style code and tested to full 280 ah. Running a 16s2p setup on a 48V mpp solar LV5048
@@alharrison3255 You are correct, elsewhere in the comments here, I have linked to the new company she started with her husband. Good service, good prices, and she doesn't exaggerate (aka lie) to sell you a product. At the time I purchased my cells, she worked at Xuba, now she has her own company at szluyuan.en.alibaba.com/
Dude, fantastic test ! Yes in the industry we're using automatic expensive equipment to cycle cells for test, but the test seriously boils down to what you have done - GREAT ! IF you are planing on using prismatic cells long term I would only suggest to provide a box that applies pressure to prevent cell swelling, but I think this is redundant since you seem to know what you are doing !
Great Job ! I’ve gotten 280Ah 3.2v Lithium Phosphate from AliExpress about 108.00 each and I asked if they were grade A or B and the seller wrote back Grade A being made as they were written ! I have not tested
As an Australian, planning out batteries is a challenge. Throwing money at the problem, yeah I can get battle-born's. But that's AU $1300, not including shipping. Local suppliers appear to charge similar prices for what the US market would call the B-grade to Battle-born.
Per the spec sheet from Eve, two are 2019 manufacture, and two are 2020 manufacturing date. Lower volume places frequently have stock sitting on the shelf a while, all of mine from a different vendor were manufactured in the same batch in the second half of 2020. Depending on the state of charge, sitting on the shelf for extended periods of time can lower capacity and lifespan. I suspect what you received was just two older cells, and everything passed all the manufacturing tests at the time, rather than grade b cells. I am sure they are not matched cells, which is different from grade a cells. It is actually quite difficult and time consuming to match cells, since the most commonly used measurement device for doing so clearly states it is not accurate above 100 amp hour cells.
Thanks for the review. Such cells seem good and powerful, I even used them for welding directly. They have the or near the stated capacity. What we should research is their life-cycles. This is the only way to see if they are viable or not. You can find cells apparently with excellent specs that do even beyond the specs in initial tests but they quickly drop capacity after only a few full discharges. I've seen this in some cheap and apparently very good Li-Ion 26650s. I don't have the means to do an efficient cycle test on high capacity LiFePO4s. I doubt they get anywhere near the stated cycles.
I love the way how you concetrate the right infos in your video and focus. Well done ! I wish every youtuber would do that. I am waiting for my cells coming from China in a few weeks and i gonna build myself a 24 200ah solar battery pack for my camping van. I am looking for how to test my cells the right way so i know what i got for my money.
@@LithiumSolar It can take sitting at that level for quite a long time to balance them as you increase the number of cells. With 4 you might not notice as much, but when you have 8 or 16 cells in parallel they won't really be balanced. I believe it is due to resistance.
Note that the straight forward method of connecting cells in parallel isn't the best. Reversed blocks of two is optimal, according to this author: www.solar-electric.com/lib/wind-sun/Iota_balanced_charging.pdf
The aluminum canning is connected to positive. Would you build a pack like your present with an additional isolation between the cells for RV DIY battery builds. Thanks for your opinion Bob
Yes, I would put a spacer between the cells in a permanent installation. I wouldn't rely on the plastic wrapping alone, especially in an installation where vibration is present.
That is a lot of eneregy storage and charge cycles for the money! What I don't like is the 6mm lug screws and the few threads that actually thread into the aluminum lugs. I built a battery using 240 ah cells purchased directly from Shenzen RJ Energy. One of the lugs stripped out even though I am very careful when tightening, but I was able to tap a larger screw into it and salvage the cell. I built a custom insulated boz with a silicon pad heater in it so it stays warm in cold weather. I have used this battery in my RV for 2 years now and it has worked perfectly with 400 w of charging PV's on the roof. I have never run the battery out when boondocking for weeks on end in the summer and up to one week even in late October in NE Washingon. The 280 ah cells you have are about half the cost of the 240 ah's I bought in 2018. They are a great value if you are capable of building it yourself. I think the fragile lugs make it best for stationary installs like a remore solar cabin , and less desirable for vibration uses like an RV. I check my lugs all the time and so far so good, but I think its just weak for high vibration uses.
Thanks so much for classroom technical data on these batteries. I currently have 2 200ah AGM batteries. They charge up great and fast (no complaints) I just have 70 (max) of only one battery for usage. I live full time in my van and after 1 year full time I’m ready 4 a change. I just can’t afford 2 Battleborn type lithium. Thanks 4 great post and channel. Look forward to more videos on this subject.
Because I had a red cable with 2 lugs crimped on already and didn't want to cut it in half for the breaker. This was a test setup. It's best to use a double-pole breaker in DC battery installations.
Can you do an update on this brand of cells? The video is about 4 months old are they holding up? I am thinking of buying but endurance is my concern on Chinese batteries, thanks
Didn't find anyone mention the numbers, but if you add in the line losses, you'll be closer than than 271ah mark. Still not crossing the 280ah barrier though. In future, if possible, for a testing rig, try shorter cables to reduce line losses?
@@dansmith6990 Basically with unmatched cells, the lowest capacity cell is the max capacity of your pack. Some cells are also "runners", meaning that they change voltage rapidly just before full or empty, thus cutting a little off the top or bottom of the complete pack as well. Most packs of 280AH cells I have seen get from 250AH to 270AH due to these mismatches.
@@tariqalmutairi1403 actually, rack batteries are so cheap now I’d buy them so I have a warranty & a professional looking installation. I saw 48v 100ah rack batteries for $1150 recently.
Thanks for the video. At first, I thought it was going to turn out bad when they didn't quite match in terms of build. But the results aren't too bad. Definitely didn't scare me away from ordering some.
You commented on the heat build up and forgive my answer I did not spend a lot of time on research but is probably lost amps due to this. Reducing the Amount of Power Lost as Heat in Wires On the previous page we saw that transmitting serious amounts of power down an electrical wire at 230 Volts would result in incredible amounts of heat being lost in the wire. What can be done to help? The power lost in an electrical wire is governed by the equation Power = Current squared x resistance. So to reduce the power loss, we just have to reduce either the current or the resistance. To reduce the resistance of a wire, we need to make it larger. There will be more metal to carry the current, so the resistance will be lower. Unfortunately, we would soon end up with an enormous wire, which would be hideously expensive. The better solution is to reduce the current. This has the advantage that if we can reduce the current by ten times, we will reduce the power loss by a hundred times! (Remember, power loss in wires is equal to current squared times resistance.) How do we reduce the current and still transmit the same power? Simply increase the voltage. Remember, Power = Voltage x Current. If we increase the voltage by 10 times, we reduce the current by 10 times, and this reduces the power lost in the wire by 100 times. So let's go back to our small town using 23MW of power. If we tried to transmit that power to the town at 230 volts down wires with a resistance of 1 Ohm, it would have needed 100,000 Amps of current, resulting in 10,000MW of power loss. However, what if we used a High Voltage power line running at 132,000 volts? (132kV) This would reduce the current required to just 174 Amps. Transmitting this down a wire with a resistance of 1 Ohm would result in just 0.03MW of power lost as heat. To provide 23MW to our town, we would have to send 23.03MW down the power line. The longer a wire is, the higher its resistance will be. If a piece of wire has a resistance of 1 Ohm, then a piece of wire twice as long will have twice the resistance, i.e. 2 Ohms. This means that longer wires lose more power due to resistance, so the further you transmit power, the more you lose as heat. Clearly, you would be mad to try and send electricity a long distance at low voltage. You would use a high enough voltage to reduce power losses to an acceptable level, and that's exactly what happens in real life. But how do you change the voltage? As I said earlier, the two ways of generating electricity are direct current or DC, and alternating current or AC. The reason why we use AC in our homes is that it is easy to change the voltage, whereas with DC it would be very difficult.
Question please, why do you take the battery all the way until the BMS shuts off to get the current? I would think a 12v battery pack you will need the 12 v to power devices as many items wont work below about 11.5 to 12 volts so then I would think when the total battery pack is at the 12 v or 11.5 v then thats the real amount of current that is real? As you really don't want to take the battery in to DOD even these are LIFEPO4 and can handle doing a DOD point I would stop at the 11.5 or 11.75 volts?
The low cutoff point defined by the manufacturer is 2.5V per cell or 10.0V for the 4s battery. The whole point of this video was to test the capacity of the batteries, and you can't do that with out a full depth of discharge ;) I would agree, in typical use scenarios, don't do a 100% depth of discharge and it will last longer.
JFYI - for common metric thread sizes (M2 - M24+) you don't have to mention thread pitch.. it's not as complicated as the imperial system. Only in rare cases the thread pitch differs from the standard and it usually involves custom applications (say optical instrument optical path threads) or some designer wants to make sure that a certain grade bolt is being used (car seats for example need hardened bolts in my car and thus come with a non standard M10 thread pitch of 1.25 mm instead of 1.5 mm).
Question for you. I have heard that if it was stored for a while then it needs to be cycled a couple times to pull full capacity. Does this seem to be true?
These cells do seem to settle down to more consistent results after a couple of higher rate charge and discharge cycles, but as someone already explained, they also need to be cycled every 6 months when stored. The QR codes indicate that two of the cells were manufactured before December of 2019, and likely sat on a shelf without being cycled.
Of course. You can order and have it shipped pretty much anywhere. If the supplier doesn't ship to your country, you can use a 3rd party freight forwarder. I've used both methods.
Using a BMS (not a balancer, they are different) ensures that all cells in series are at the same voltage and will shut down the battery in the event of over voltage, under voltage, over current, and several other parameters
Off Grid Garage has been running heaps of tests with these 280AH LFP. I think he has ordered from Shenzhen Basen and they seem to have a small factory. Alibaba has tabs with company profile stuff. There may be other larger factories. Merit Sun has a YT video and they have a very advanced facililty. You have all these people dissing Chinese batteries but the tech says the Chinese are the leaders. You have to sort of figure out who the supplier is, whether they produce the cells or resell, stuff like that. To me this pricing is 'for real' and I love LFP so this is good. There was an article last week on pack prices for LFP at $100 a kwh. It all fits together. See if you can find a factory or a supplier and get comfortable with them. These cells are OK but I'd rather have fresher and from a matched batch. There's a long way to go with this stuff.
Great video, question: can I lay the cell side way? Will it leak or effect performance? I am building a power box and laying side way give me more room to play with , thanks
It's generally accepted that the prismatic batteries can be placed in any orientation other than upside down. You should consult the manufacturer's specifications though for the specific cell you have.
The 2019 spec sheet for the cells says (in testing section), that the capacity is only valid for one month after leaving the factory and before 5 cycles (charge/discharge cycles). This leaves an obvious out for the manufacturer to say it meets spec, you just tested wrong. I think everyone would be happier if they just rated it realistically (like Leishen rates an almost identical cell as 272AH). I have 16 of the Eve cells, and I am running capacity tests now.
so you are roughly 104wh short on capacity if you ran the test for 4 hours 26w of heat was generated by the bms, wire and breaker. i think if it wasent for these loses you would have got full capacity. do you think that 26w of heat across those three components is accurate?
does having them connected in parallel automatically balance them? (assuming the voltage is near identical when you connect them so it doesn't blowup) nvm I see several studies that say they should be left in parallel a few days before building a battery
The amp rating of the BMS does not need to match the amp-hour rating of the battery. The BMS just needs to be equal to less than the maximum continuous discharge rating of the battery per the manufacturer's data sheet. This BMS is rated for 100A discharge and I don't plan to ever consume more than 100A.
Part of the capacity loss would probably have been the wire used...When you first start the test, if the wire gets warm, its telling you that the gauge is not low enough and you have a bottleneck. When that occurs you are wasting energy in heat. Bigger wire (2 gauge) and retest. I also would never keep draining those cells past 2.5 volts, as there is little to no energy left after that point, and you are stressing the cell by doing this.
I'm on the more patriotic side of things generally, but what the heck is up with all these EVERYTHING FROM CHINA IS TERRIBLE comments? And why do they generally seem to be sock puppet/troll accounts? Anyway... like others have said, thanks for (potentially) taking the hit and trying these batteries out. I've also been looking into off-grid options, and this info is extremely helpful and interesting.
I wouldn't say everything from China is junk, but when you order from a non-branded store that may not care about developing a good reputation with buyers you may end up with junk that nobody else wanted mis-marketed. This happens with such frequency that it isn't surprising that they were under capacity or mis-matched. What was surprising was that they were as close as they were. China can, and does make high-end products. They just come with much higher price tags and are usually sold by "reputable vendors" By that phrase I don't mean something like Rolex, or Nike. I mean a vendor that cares about fostering a good reputation. Think of it like this. The DMV doesn't really care about the reputation. You can spend well over an hour waiting there and it is considered normal. Starbucks does care. If you spent an hour there it is because after they got your drink made for you in about 5 minutes, they provided an atmosphere that you wanted to stay at. The same situation happens with e-commerce stores. Some spend a great deal of time fostering an atmosphere and trust. Others don't. Alibaba is like E-bay, with less buyer protections. Sometimes you get lucky. I've gotten lucky before. Sometimes, you don't get lucky.
Can you run a charging test to see how well it balances without the balancer? Likely they should charge pretty evenly, mostly the BMS should not be needed?
This battery stores 3584Wh of energy. You'll need to know how much power your fridge consumes. You can measure this using something like a KillAWatt amzn.to/37DCXEL because a fridge will not be running the entire time (compressor starts/stops depending on cooling demands). Once you know the hourly consumption of the fridge, take (3584 * 0.80) / FridgeHourlyRate = number of hours the batteries will last. The 0.80 multiplier is to account for the losses inverting from DC to AC.
0:12... is that each or for all 4 ? After your initial power test I would have recharged the batteries and done the test for a 2nd time to verify the results since you dis not start with depleted batteries with the first test.
So you were 10ah short but are you factoring in the losses through the cables and also the fact that the BMS may be losing some AH as it's balancing too? It doesn't seem that far out to me! The fact that 2 of the cells appear to be different is a bit suspect though - be interesting if you tested each cell to see if maybe those 2 suspect cells are dragging the for the pack as a whole.
nowhere on the listing do I see it says grade A, these are in fact grade "whatever" cells, how much was shipping though? if they capacity test ok than $400 is freaking a great deal on used 280ah cells man
@@LithiumSolar $464-ish for 4 cells is not bad, but the mismatched construction on half of them worries me, one set could be older or have a totally different design. I've heard the "seller told me it was grade A" story before on the diysolar forum. if the listing does not specify grade A than it is not grade A. apparently in china the seller is allowed to lie to your face but not in writing. well except for UL certifications because they're not made in US. the real grade A cells specifically say it in the listing and some even state the date of manufacturer. those QRL/barcode stickers are fake, they applied new wrapping to used cells. do I have proof? no but what does your intuition tell you?
@@LithiumSolar here's an example of what's more likely to be grade A: "Date of production: Feb 2020" www.aliexpress.com/item/4001016025169.html?spm=a2g0s.8937460.0.0.30b82e0eAplSBF actually here the 280ah version www.aliexpress.com/item/4000450142400.html?spm=a2g0s.8937460.0.0.30b82e0eAplSBF
Nice test and clean setup. Clearly resistance losses don't affect amp hour testing, they become part of the load and only reduce watt hours measured. The accuracy of the amp-hour measurement (including shunt, shunt voltage measurement and time accumulation accuracy) would need to be verified to validate the overall amp hour accuracy. These cells could be within spec and the result error (-2.9%) within instrumental accuracy. Batrium mentions 1% typical accuracy for the shunt component alone and "typical" isn't a worst case guaranteed spec, plus this must be added to the inaccuracy of the measurement subsystem. Not a bad result.
Thanks for this! You mention that your circuit breaker was getting warm, but I notice that the shunt is not measuring any power consumption by the breaker itself, as it is wired after the breaker. You might want to change this, and install the shunt as the first item from the battery, that way you'll be recording any power that the breaker consumes. Perhaps that is where your missing amp-hours escaped to... Cheers.
Great breakdown ... one thing has me ... Building a powerwall is straight forward, I'd like to see an Automatic Transfer Switch for Grid to Battery power, I have a 200amp service, but the only ATS I can find seem to be 100amp, should I take the feed-in from the grid and split it one to a sub-panel powered by the ATS, separating out the circuits I want to power from Batteries?
I should add that when I got them, I hooked 18 of them in parallel and used my iCharger x8 to do a 1s charge to 3.65vdc. it took about 3-4 days, lol. it was awesome though.
Good test. I wouldn’t be cut up about about 96.4% of the rated capacity since by your own admission there were heat losses (resistances) in your circuit that happen before the current shunt. Well done though and thanks for a good review.
Yes, you can connect a charger and inverter at the same time. If load exceeds charger output, the battery will discharge. If load is less than charger output, the battery will charge.
I'm not sure why you would get a modified sine wave inverter. Also does it not matter that it is a 100a BMS and the batteries are capable of almost 3 times that. I'm curious because I plan on getting four of those cells, but I'll never use more than 100a so is it ok to use that BMS on those? I guess if it went over it would just trip? Not sure, sorry still new to this.
I suspect you are losing at least 3-5% of the battery power from Cables, BMS and Circuit breaker. I always try to double the ampacity of any device that passes the full current to the output. So in your case you would need bigger cables that are designed to handle at least 160 amps, probably 2 ga to 0/0 ga for that run length at that voltage. The BMS should be 150-200 amps rated. And at least a 150 amp fast trip circuit breaker. All these together should reduce your losses to heat generation in the components by up to 50 watts. If you did a direct capacity test on the battery you would likely see just over rated capacity, with no hardware in between. Keep up the good work, and Merry Christmas :)
Ciao grazie per i tuoi video sono davvero molto interessanti. Ti volevo chiedere secondo te è meglio installare delle batterie LTO oppure delle batterie lifepo4? Da quello che ho capito dal tuo video e dai tuoi commenti le batterie lifepo4 fanno una scarica di corrente limitata a max 0.3 C per non danneggiarle. Ma soprattutto la temperatura esterna quanto deve essere per non rompere le batterie? Spero tu mi risponda nel frattempo ti ringrazio. ☺️
The manufacturer doesn't recommend using those BMS products with anything more than 100ah last time I checked about a year ago. Has this changed? They don't have much balance power. 200ma total I think. Maybe that is for 16s, not sure but it would be nice if this was at leasts discussed.
Hello. I have a question. I have a 250amp AliExpress battery plus his 250amp Daly BMS. When I'm charging, I have 14.1 out of the charger and in the BMS But, out the BMS (P+) I only have the battery voltage 12.9. and it's not increasing Am I not supposed to have 14.1 or more than the battery voltage out of the BMS? Thanks
Well done. Do you think two 12v configurations could be wired in parallel to work with an existing 12v system? Looking to replace a set of 12v AGM batteries.
Yes, you could wire two 12V in parallel. You will need 2 BMS that way though. I would first wire the cells in groupings of two (parallel) then wire those in series such that you only need one BMS (4s2p). As for replacing the AGM batteries - you will need to check that the device supports LiFePO4 batteries to prevent over charging/discharging.
@@patrickmchargue7122 newer models of the Daly BMS like he used have low temperature cut off, but you have to ask for it when ordering. Newer models can also be purchased with Bluetooth and USB ports for monitoring and changing parameters, but again, you must specify when ordering.
What's wrong by charge them in series? I replece the lead cells on a power back up with 4 blue cylindrical lifepo wired them in series without a BMS. till now work fine. They had outperform the original specs. Although they have not been fully charged at 100% the v out was 13.? not 14.4. Now I'm planning on buying 4 cells like these to replace my car battery.
thank you so much, I am planning to build a DIY power box using these 4 of these 280AH cell. Learning from your last video, i will need 4x280ah battery cells, 150A BMS, MPPT Charger, 2000 Pure sine inverter... how many fuses or breaker do i need for safety measure and where is best to put these fuses? Will i also need some kind of relay circuit device? what is the recommend wire sizes?
First, THANK YOU VERY MUCH for taking the time, spending the money & doing all of the 'heavy lifting' of testing these cells (that I was sooo excited about!) I'm more than a little disappointed that the cells varied by so much? Clearly, 2 cells came from a single batch, and the other (2) came from another. They varied enough that I wondered if 2 of the cells were from say 'version A' and the other 2 came from a more recent & improved lot. That being said:
* I probably would've used a lower gauge wire to reduce losses (say 6 AWG or even a 4 AWG)?
* I may've tried to do a .2C test, but- really I'm being a nitpicker, and, the wiring mentioned above would've been less of an issue, but...
* I thought each cell was limited to 2.5v, so I was surprised to see 2.2v as the bottom? Asking?
* Would it have helped to parallel the cells for a day or so- for the BMS & preventing the need for a bottom balance?
* Do you think it might've performed slightly better (275 -280AH) if you had bottom balanced?
Great test, great review & THANK YOU 1,000 times!!! I genuinely appreciate your efforts. Noted: another gentleman purchased 16 cells for a garage solar power project and he only was able to get @ 250AH or so. Perhaps they are slightly less powerful and they DO have limitations (none that will disturb me using them..) But, they still have a TON of stored power & the chemistry lasts for so many cycles!!!
Dave
Its the role of the BMS to handle balancing for you.
Having the cells connected to a bms for a day should give you the same result as connecting them parallel - they should get balanced.
And a BMS is safer since it wil reduce/regulate the balancing current.
* Thanks!! :)
* The read/black cables coming off the battery were 4 AWG. The black cable from the shunt to the inverter was 1/0 AWG as I already had a piece with ring terminals crimped on.
* One thing I find interesting about the prismatic LiFePO4 batteries I've looked at is the capacity is usually given at a 1C discharge. I find that hard to believe, but I haven't tried a 1C test to see what happens. With this in mind, I think a 0.28C test is close enough to 0.2C commonly used by NMC chemistries. Lower amps may have resulted in another Ah or two, not sure.
* The spec sheet for these batteries gave 2.5V as the low cutoff. The BMS was set for 2.2V. I can't change it for this particular BMS and wanted to leave it go to see what would happen (if the BMS would shut off). The voltage drop at that point in the discharge curve is so steep that the extra between 2.228V and 2.50V didn't make much of a difference.
* Yes! I do think paralleling beforehand would have helped. I will be testing this later this week to see if there is any difference. I will report back my findings. I don't think the iCharger balanced long enough even though I had it set to "slow balance".
@@LithiumSolar I hope that you understand that I'm NOT questioning you in a 'snarky' way, I'm really trying to learn more (and, I'm more of a NOOB!) while being 'clear' instead of loose. Thanks (again!!!) for buying & testing these- I so appreciate all of your efforts! I was planning on using (2) Bluetooth programmable BMS' recommended by Will Prowse & paralleling them on arrival, discharging to a lower state of charge, balancing- charge & do a .2C rate test. .28C is so darn close- it thought it was higher (my bad!) Either way, 271AH is purdy darn close & still an exceptional value. I DO wish you had received 'matched' cells by lot as well as charge profile & resistance but at that price- it may be too much to ask! Hahaha
@@hubertnnn I think that Daly BMS' only charge at the very top of the charge cycle, and, often needs several charge cycles to balance the cells. When installed, the cell voltage variance was too large for it to even work. The resistors are pretty small on most BMS' that I've ever seen. With such a flat discharge curve, the amount of voltage in each cell can be pretty large -especially in 280AH prismatic cells!
@@DCGULL01 being snarky didn't even cross my mind... Out of all the comments, yours was the one I pinned lol. I am not an expert and am here to learn too. One reason I make these videos is I love reading through the comments, ideas, hearing what others are doing, etc. I do agree, 271Ah is still fantastic - I guess I just expected to see the full 280Ah after what I've been reading from others. I'll be ordering my next batch from Basen (seems to be who most are recommending) and getting 16 at once. Hopefully those will be matched. I love the Daly BMS for small builds and testing, but I'll be using a Batrium on my final production setup :)
You got 97% of the rated capacity, and your breaker and negative cable were generating some heat. The 300 mV drop from the terminals to the shunt is also about 97% of the voltage, so the cells seem to be pretty close to 280Ah. And for that price, seems like you did well!
The losses in cables, breaker etc do not affect Ah-measurement. The shunt measures the current going through the circuit and it does not matter where the energy is dissipated, whether in the actual load or elsewhere.
@@mcg6762 Errm. No. I don't believe that is accurate. Any losses between the terminal and the shunt (which is where my comment clearly identified the 300mV loss) is dissipated as heat before it any measurment by the shunt. That 300mV X (the amps) equals power lost at any moment, and power lost over a period of time is lost energy. See the First Law of Thermodynamics--the Law of Conservation of Energy for more info.
@@daveduncan2748 Ah is different from Wh. The shunt measures current. All current must go through the shunt, regardless of where the voltage is dropped.
@@mcg6762 i think he is sating you would need a shunt at each separate hot device to catch what its individual loss is.
@@The2000redrocket If you have more than one shunt in the same series circuit they would all measure the same current. Basic circuit theory. The current is the same everywhere for a straight series circuit.
I've watched a few of these for the 280 ah and most get the 280 or close with all the wiring and such 271 seems close enough for me. You do great work thanks.
The bms cuts out at 2.28v so he didnt pull the max ah from the batteries
At that price i would say close enough for the AH.
Agree!
Yup!
heck yeah
Wow! a most excellent video. Great production. Lighting, audio quality, and your narration. Just easy to watch, and appreciate your thoroughness. Going to watch more of your channel. Thank you!
I've been debating selling my 16s NMC pack and dropping $10k or so on a massive bank of these. I don't like that they don't even have the rated capacity out of the box though. Thanks for digging into them!
Find the good seller, based on reviews mostly... 16 batts should be around 1.5k!
@@domatic 15k vs 1.5k
I do believe the chap said the bms cuts out at 2.28V not 2.2v so how can you say the batteries are not at the rated capacity?
Man, great video. Your whole presentation was straightforward and no fluff. Keep up that great work.
Your video shows the value of a testing setup and spend time on balancing and discharge testing new batteries. Thank you
hello, after one and half year, i would like to know how it's going on? how many cycles? and how many Ah left?
Tks.
Not sure about your datasheet, but Off Grid Garage found that his 'manual' said to let the cells sit for an hour after charging before starting the test or something like that.
yes I heard 30 mins, so 1 hour is probably more correct
Thanks for the review. I just ordered 4 280Ah cells from an eBay seller for about $170/cell, so not as good of a deal as yours... I’m just hoping they are matched, new cells, as they were advertised! This makes such a nice, compact, high capacity battery. Even at what I paid, it will be cheaper per usable amp hour than purchasing AGM batteries (considering 80% DOD for the LiFePO4 and 50% for the AGM). Thanks again for the review/capacity test!
Many users are buying from this resller called XUBA and specifcally asking for AMY as there rep. I bought 32 all same qr style code and tested to full 280 ah. Running a 16s2p setup on a 48V mpp solar LV5048
I bought from the same source (Amy at Xuba) and got pristine cells as well.
Amy is no longer with Xuba, she's now with Shenzhen Luyuan.
@@alharrison3255 You are correct, elsewhere in the comments here, I have linked to the new company she started with her husband. Good service, good prices, and she doesn't exaggerate (aka lie) to sell you a product. At the time I purchased my cells, she worked at Xuba, now she has her own company at szluyuan.en.alibaba.com/
@@john_in_phoenix I didn't read every post, so I missed yours.
@@alharrison3255 not a problem. I make no money from recommending her, I am just a satisfied customer.
Dude, fantastic test ! Yes in the industry we're using automatic expensive equipment to cycle cells for test, but the test seriously boils down to what you have done - GREAT ! IF you are planing on using prismatic cells long term I would only suggest to provide a box that applies pressure to prevent cell swelling, but I think this is redundant since you seem to know what you are doing !
Great Job ! I’ve gotten 280Ah 3.2v Lithium Phosphate from AliExpress about 108.00 each and I asked if they were grade A or B and the seller wrote back Grade A being made as they were written ! I have not tested
As an Australian, planning out batteries is a challenge. Throwing money at the problem, yeah I can get battle-born's. But that's AU $1300, not including shipping. Local suppliers appear to charge similar prices for what the US market would call the B-grade to Battle-born.
How are the cells doing after 3 years? Thanks for the video.
Good. They're still sitting on the shelf :) :)
@@LithiumSolar ohh, so you never used them(?)
@@extendedp1 Correct. I test a LOT of batteries on this channel, more than I have an actual use for.
Per the spec sheet from Eve, two are 2019 manufacture, and two are 2020 manufacturing date. Lower volume places frequently have stock sitting on the shelf a while, all of mine from a different vendor were manufactured in the same batch in the second half of 2020. Depending on the state of charge, sitting on the shelf for extended periods of time can lower capacity and lifespan. I suspect what you received was just two older cells, and everything passed all the manufacturing tests at the time, rather than grade b cells. I am sure they are not matched cells, which is different from grade a cells. It is actually quite difficult and time consuming to match cells, since the most commonly used measurement device for doing so clearly states it is not accurate above 100 amp hour cells.
Thanks for the review. Such cells seem good and powerful, I even used them for welding directly. They have the or near the stated capacity. What we should research is their life-cycles. This is the only way to see if they are viable or not. You can find cells apparently with excellent specs that do even beyond the specs in initial tests but they quickly drop capacity after only a few full discharges. I've seen this in some cheap and apparently very good Li-Ion 26650s. I don't have the means to do an efficient cycle test on high capacity LiFePO4s. I doubt they get anywhere near the stated cycles.
I love the way how you concetrate the right infos in your video and focus. Well done ! I wish every youtuber would do that. I am waiting for my cells coming from China in a few weeks and i gonna build myself a 24 200ah solar battery pack for my camping van. I am looking for how to test my cells the right way so i know what i got for my money.
btw. if you hook up all cells in parallel for a day while charging it as a 1s4p pack, you will have perfectly top balanced cells to start a test with.
I will be doing this and re-testing out of curiosity later this week :)
@@LithiumSolar It can take sitting at that level for quite a long time to balance them as you increase the number of cells. With 4 you might not notice as much, but when you have 8 or 16 cells in parallel they won't really be balanced. I believe it is due to resistance.
@@LithiumSolar The results would be interesting thank you.
Note that the straight forward method of connecting cells in parallel isn't the best. Reversed blocks of two is optimal, according to this author: www.solar-electric.com/lib/wind-sun/Iota_balanced_charging.pdf
The aluminum canning is connected to positive. Would you build a pack like your present with an additional isolation between the cells for RV DIY battery builds.
Thanks for your opinion
Bob
Yes, I would put a spacer between the cells in a permanent installation. I wouldn't rely on the plastic wrapping alone, especially in an installation where vibration is present.
@@LithiumSolar What material do you recommend? What thickness?
Very comprehensive test , nice to follow with good explaining and commentary. Nice equipment also.
That is a lot of eneregy storage and charge cycles for the money! What I don't like is the 6mm lug screws and the few threads that actually thread into the aluminum lugs. I built a battery using 240 ah cells purchased directly from Shenzen RJ Energy. One of the lugs stripped out even though I am very careful when tightening, but I was able to tap a larger screw into it and salvage the cell. I built a custom insulated boz with a silicon pad heater in it so it stays warm in cold weather. I have used this battery in my RV for 2 years now and it has worked perfectly with 400 w of charging PV's on the roof. I have never run the battery out when boondocking for weeks on end in the summer and up to one week even in late October in NE Washingon. The 280 ah cells you have are about half the cost of the 240 ah's I bought in 2018. They are a great value if you are capable of building it yourself. I think the fragile lugs make it best for stationary installs like a remore solar cabin , and less desirable for vibration uses like an RV. I check my lugs all the time and so far so good, but I think its just weak for high vibration uses.
What about performance after 3 years?
Maybe in the trash
Please give details for the display you used to monitor the voltage
271 is quite close & good for first run. Your readings might possibly be off by 1 or 2 % anyway. Several cycles should increase the measurements.
also count the BMS and cable loss
Thanks so much for classroom technical data on these batteries. I currently have 2 200ah AGM batteries. They charge up great and fast (no complaints) I just have 70 (max) of only one battery for usage. I live full time in my van and after 1 year full time I’m ready 4 a change. I just can’t afford 2 Battleborn type lithium. Thanks 4 great post and channel. Look forward to more videos on this subject.
I was wondering what is the reason for placing your circuit breaker on the negative side of the battery rather than on the positive side ?
Because I had a red cable with 2 lugs crimped on already and didn't want to cut it in half for the breaker. This was a test setup. It's best to use a double-pole breaker in DC battery installations.
Can you do an update on this brand of cells? The video is about 4 months old are they holding up? I am thinking of buying but endurance is my concern on Chinese batteries, thanks
Didn't find anyone mention the numbers, but if you add in the line losses, you'll be closer than than 271ah mark. Still not crossing the 280ah barrier though. In future, if possible, for a testing rig, try shorter cables to reduce line losses?
Very good review.
400mV difference between cells at the end of test seems too much.
Clearly not mached cells.
I'm sure if you pay an extra $100/cell, you could get matched cells. Most people prefer cheaper price and "good enough" or "close enough".
@@john_in_phoenix What is the real world issue with unmatched cells? Just curious since I don't know much
@@dansmith6990 Basically with unmatched cells, the lowest capacity cell is the max capacity of your pack. Some cells are also "runners", meaning that they change voltage rapidly just before full or empty, thus cutting a little off the top or bottom of the complete pack as well. Most packs of 280AH cells I have seen get from 250AH to 270AH due to these mismatches.
Love that battery monitor app on your tablet... where can we get it ? Thanks !
It's something I put together myself using a Batrium BMS shunt and Grafana graphing software.
@@LithiumSolar Would be cool if you could github that for us.
so now Amy has LF280N Has anyone received these new better 290Ah batteries?
I’m going to build this batt, you’re the 2nd vid I’ve seen about this & for the price, you can’t go wrong 👍👍
hey, two years later, are they good ? do you recommend that i buy ?
@@tariqalmutairi1403 actually, rack batteries are so cheap now I’d buy them so I have a warranty & a professional looking installation. I saw 48v 100ah rack batteries for $1150 recently.
How can you see batrium info on a tablet i can figure it out how to do it?
Hello....what are the advantages of adding one more battery, from 16S to 17S, and raising it to 51v?...Thanks
Thanks for the video. At first, I thought it was going to turn out bad when they didn't quite match in terms of build. But the results aren't too bad. Definitely didn't scare me away from ordering some.
Pourquoi les câbles bleus et noirs négatifs sont petit ? 6AWG pour 150A ???
What kind of longevity do you expect? Does the company claim an amount of cycles?
Can you charge each cell to the same capacity before wiring them together?
You commented on the heat build up and forgive my answer I did not spend a lot of time on research but is probably lost amps due to this.
Reducing the Amount of Power Lost as Heat in Wires
On the previous page we saw that transmitting serious amounts of power down an electrical wire at 230 Volts would result in incredible amounts of heat being lost in the wire. What can be done to help?
The power lost in an electrical wire is governed by the equation Power = Current squared x resistance. So to reduce the power loss, we just have to reduce either the current or the resistance. To reduce the resistance of a wire, we need to make it larger. There will be more metal to carry the current, so the resistance will be lower. Unfortunately, we would soon end up with an enormous wire, which would be hideously expensive.
The better solution is to reduce the current. This has the advantage that if we can reduce the current by ten times, we will reduce the power loss by a hundred times! (Remember, power loss in wires is equal to current squared times resistance.)
How do we reduce the current and still transmit the same power?
Simply increase the voltage. Remember, Power = Voltage x Current. If we increase the voltage by 10 times, we reduce the current by 10 times, and this reduces the power lost in the wire by 100 times.
So let's go back to our small town using 23MW of power. If we tried to transmit that power to the town at 230 volts down wires with a resistance of 1 Ohm, it would have needed 100,000 Amps of current, resulting in 10,000MW of power loss. However, what if we used a High Voltage power line running at 132,000 volts? (132kV) This would reduce the current required to just 174 Amps. Transmitting this down a wire with a resistance of 1 Ohm would result in just 0.03MW of power lost as heat. To provide 23MW to our town, we would have to send 23.03MW down the power line.
The longer a wire is, the higher its resistance will be. If a piece of wire has a resistance of 1 Ohm, then a piece of wire twice as long will have twice the resistance, i.e. 2 Ohms. This means that longer wires lose more power due to resistance, so the further you transmit power, the more you lose as heat.
Clearly, you would be mad to try and send electricity a long distance at low voltage. You would use a high enough voltage to reduce power losses to an acceptable level, and that's exactly what happens in real life.
But how do you change the voltage? As I said earlier, the two ways of generating electricity are direct current or DC, and alternating current or AC. The reason why we use AC in our homes is that it is easy to change the voltage, whereas with DC it would be very difficult.
The price on these are almost 400$ for 4 batteries. The price you quoted was per battery maybe?
Yes, they are sold in packs of 4. Sorry I wasn't clear with my pricing.
Good morning. Can I use a 150Ah BMS on a 206Ah battery?
on the alibaba link you posted, is the cost for one cell $332? or is that for a pack of 4 cells?
The price is for 4 cells
@@LithiumSolar thank you✊
hello, what tightening cut of the connection screws
Question please, why do you take the battery all the way until the BMS shuts off to get the current? I would think a 12v battery pack you will need the 12 v to power devices as many items wont work below about 11.5 to 12 volts so then I would think when the total battery pack is at the 12 v or 11.5 v then thats the real amount of current that is real? As you really don't want to take the battery in to DOD even these are LIFEPO4 and can handle doing a DOD point I would stop at the 11.5 or 11.75 volts?
The low cutoff point defined by the manufacturer is 2.5V per cell or 10.0V for the 4s battery. The whole point of this video was to test the capacity of the batteries, and you can't do that with out a full depth of discharge ;) I would agree, in typical use scenarios, don't do a 100% depth of discharge and it will last longer.
I've got a question. Wouldn't be better using M6 aluminium studs? Preserving the cell's threads.
Hi hi, for your first link to alibaba, it says they ship out within 7 days. Was your delivery time pretty good?
It took about 7 weeks for it to arrive after day of payment from what I recall. I used sea freight (cheapest method).
JFYI - for common metric thread sizes (M2 - M24+) you don't have to mention thread pitch.. it's not as complicated as the imperial system.
Only in rare cases the thread pitch differs from the standard and it usually involves custom applications (say optical instrument optical path threads) or some designer wants to make sure that a certain grade bolt is being used (car seats for example need hardened bolts in my car and thus come with a non standard M10 thread pitch of 1.25 mm instead of 1.5 mm).
Interesting info, didn't know that, thanks! The metric bolts/screws sure are easier to remember and pick out in the hardware store... lol
Question for you. I have heard that if it was stored for a while then it needs to be cycled a couple times to pull full capacity. Does this seem to be true?
These cells do seem to settle down to more consistent results after a couple of higher rate charge and discharge cycles, but as someone already explained, they also need to be cycled every 6 months when stored. The QR codes indicate that two of the cells were manufactured before December of 2019, and likely sat on a shelf without being cycled.
How is it dealing with alibaba anyways ?
I didn’t know being in the USA that you could deal with them
Of course. You can order and have it shipped pretty much anywhere. If the supplier doesn't ship to your country, you can use a 3rd party freight forwarder. I've used both methods.
Why do you need a balancer, when batteries are conntected in series.
Using a BMS (not a balancer, they are different) ensures that all cells in series are at the same voltage and will shut down the battery in the event of over voltage, under voltage, over current, and several other parameters
Off Grid Garage has been running heaps of tests with these 280AH LFP. I think he has ordered from Shenzhen Basen and they seem to have a small factory. Alibaba has tabs with company profile stuff. There may be other larger factories. Merit Sun has a YT video and they have a very advanced facililty. You have all these people dissing Chinese batteries but the tech says the Chinese are the leaders. You have to sort of figure out who the supplier is, whether they produce the cells or resell, stuff like that. To me this pricing is 'for real' and I love LFP so this is good. There was an article last week on pack prices for LFP at $100 a kwh. It all fits together. See if you can find a factory or a supplier and get comfortable with them. These cells are OK but I'd rather have fresher and from a matched batch. There's a long way to go with this stuff.
Great video, question: can I lay the cell side way? Will it leak or effect performance? I am building a power box and laying side way give me more room to play with , thanks
Lithium cells are not like lead acids you can place them any way and nothing will happen to them.
It's generally accepted that the prismatic batteries can be placed in any orientation other than upside down. You should consult the manufacturer's specifications though for the specific cell you have.
The 2019 spec sheet for the cells says (in testing section), that the capacity is only valid for one month after leaving the factory and before 5 cycles (charge/discharge cycles). This leaves an obvious out for the manufacturer to say it meets spec, you just tested wrong. I think everyone would be happier if they just rated it realistically (like Leishen rates an almost identical cell as 272AH). I have 16 of the Eve cells, and I am running capacity tests now.
Isnt it the same as if you bought a car that says 33mpg but when you drive it in real condition you get 25mpg?
Sorry for I didn't catch how long the test was? would be good to know thanks,
so you are roughly 104wh short on capacity if you ran the test for 4 hours
26w of heat was generated by the bms, wire and breaker. i think if it wasent for these loses you would have got full capacity. do you think that 26w of heat across those three components is accurate?
does having them connected in parallel automatically balance them? (assuming the voltage is near identical when you connect them so it doesn't blowup)
nvm I see several studies that say they should be left in parallel a few days before building a battery
That’s a small package for a lot of battery. 280 ah. Wow
Nice video. Thanks
Could you loose 9Ah in BMS->wire->hot switch->wire to shunt ?
No. You would loose Watt-hours (power) at the BMS/switch but amps will remain constant throughout the entire circuit.
four 280a batteries and 100a bms, isn't it unmatched? this is the only question. can you explain why it doesn't make problems?
The amp rating of the BMS does not need to match the amp-hour rating of the battery. The BMS just needs to be equal to less than the maximum continuous discharge rating of the battery per the manufacturer's data sheet. This BMS is rated for 100A discharge and I don't plan to ever consume more than 100A.
@@LithiumSolar Chinese Dary sells 500a BMS. In what situation, do you use this big BMS? We can pull 500a out of battery bank, cant we?
Part of the capacity loss would probably have been the wire used...When you first start the test, if the wire gets warm, its telling you that the gauge is not low enough and you have a bottleneck. When that occurs you are wasting energy in heat. Bigger wire (2 gauge) and retest. I also would never keep draining those cells past 2.5 volts, as there is little to no energy left after that point, and you are stressing the cell by doing this.
I have just purchased four cells this week through Aliexpress. Delivery 30 to 50 days :)
And the total shipping cost was how much? Every where I check the shipping is as much as the cells or the don't mention it.
The total cost was $116/cell shipped.
Can you use this as trolling motor battery?
I'm on the more patriotic side of things generally, but what the heck is up with all these EVERYTHING FROM CHINA IS TERRIBLE comments? And why do they generally seem to be sock puppet/troll accounts? Anyway... like others have said, thanks for (potentially) taking the hit and trying these batteries out. I've also been looking into off-grid options, and this info is extremely helpful and interesting.
I wouldn't say everything from China is junk, but when you order from a non-branded store that may not care about developing a good reputation with buyers you may end up with junk that nobody else wanted mis-marketed. This happens with such frequency that it isn't surprising that they were under capacity or mis-matched. What was surprising was that they were as close as they were. China can, and does make high-end products. They just come with much higher price tags and are usually sold by "reputable vendors" By that phrase I don't mean something like Rolex, or Nike. I mean a vendor that cares about fostering a good reputation.
Think of it like this. The DMV doesn't really care about the reputation. You can spend well over an hour waiting there and it is considered normal.
Starbucks does care. If you spent an hour there it is because after they got your drink made for you in about 5 minutes, they provided an atmosphere that you wanted to stay at.
The same situation happens with e-commerce stores. Some spend a great deal of time fostering an atmosphere and trust. Others don't. Alibaba is like E-bay, with less buyer protections. Sometimes you get lucky. I've gotten lucky before. Sometimes, you don't get lucky.
Can you run a charging test to see how well it balances without the balancer? Likely they should charge pretty evenly, mostly the BMS should not be needed?
Did you say $116 shipped? Is that for 4 cells? The link you provided is priced over $300.
Yes, $116 per cell. The price on the Alibaba page is for 4 cells. Add shipping and divide by 4 to get per-cell price :)
LithiumSolar Got it and thanks for making this great video!
Hi how long those battery can last to run fridge overnight?
This battery stores 3584Wh of energy. You'll need to know how much power your fridge consumes. You can measure this using something like a KillAWatt amzn.to/37DCXEL because a fridge will not be running the entire time (compressor starts/stops depending on cooling demands). Once you know the hourly consumption of the fridge, take (3584 * 0.80) / FridgeHourlyRate = number of hours the batteries will last. The 0.80 multiplier is to account for the losses inverting from DC to AC.
0:12... is that each or for all 4 ? After your initial power test I would have recharged the batteries and done the test for a 2nd time to verify the results since you dis not start with depleted batteries with the first test.
The price was per cell, so multiply by 4 :) I will be re-testing later this week after manually balancing by connecting in parallel.
I thought 2.6V was the bottom end of the safe voltage range?
2.5V. The manufacturer's datasheet will indicate this.
Do they off gas anything while charging?
No. They only vent when something is wrong, such as being massively over-charged.
That alligator balance leads is a good idea I think I'm going to have to steal that
What is the cell balancing performance(or ability) of this bms? Wouldn't it be necessary to install an equalizer(Active balance)?
So you were 10ah short but are you factoring in the losses through the cables and also the fact that the BMS may be losing some AH as it's balancing too? It doesn't seem that far out to me! The fact that 2 of the cells appear to be different is a bit suspect though - be interesting if you tested each cell to see if maybe those 2 suspect cells are dragging the for the pack as a whole.
How many batteries would I need to build a 48V 40 kWh size powerwall?
Can I use Renogy Rover MPPTs with a 280 Ah prismatic battery (4 cells)?
Where can I buy one of ur custom batteries?
What is your opinion about compressing of these battery cells
nowhere on the listing do I see it says grade A, these are in fact grade "whatever" cells, how much was shipping though? if they capacity test ok than $400 is freaking a great deal on used 280ah cells man
I specifically asked the person I worked with to place the order if they were Grade A and he told me yes.
The price I gave included the shipping cost. I think they were $116/ea shipped or something around there.
@@LithiumSolar $464-ish for 4 cells is not bad, but the mismatched construction on half of them worries me, one set could be older or have a totally different design. I've heard the "seller told me it was grade A" story before on the diysolar forum. if the listing does not specify grade A than it is not grade A. apparently in china the seller is allowed to lie to your face but not in writing. well except for UL certifications because they're not made in US. the real grade A cells specifically say it in the listing and some even state the date of manufacturer. those QRL/barcode stickers are fake, they applied new wrapping to used cells. do I have proof? no but what does your intuition tell you?
@@LithiumSolar here's an example of what's more likely to be grade A: "Date of production: Feb 2020" www.aliexpress.com/item/4001016025169.html?spm=a2g0s.8937460.0.0.30b82e0eAplSBF
actually here the 280ah version www.aliexpress.com/item/4000450142400.html?spm=a2g0s.8937460.0.0.30b82e0eAplSBF
curious as to why breaker is on the neg terminal ,, ?
That's just where I put it for this test setup. No reason in particular.
Nice test and clean setup. Clearly resistance losses don't affect amp hour testing, they become part of the load and only reduce watt hours measured. The accuracy of the amp-hour measurement (including shunt, shunt voltage measurement and time accumulation accuracy) would need to be verified to validate the overall amp hour accuracy. These cells could be within spec and the result error (-2.9%) within instrumental accuracy. Batrium mentions 1% typical accuracy for the shunt component alone and "typical" isn't a worst case guaranteed spec, plus this must be added to the inaccuracy of the measurement subsystem. Not a bad result.
Thanks for this! You mention that your circuit breaker was getting warm, but I notice that the shunt is not measuring any power consumption by the breaker itself, as it is wired after the breaker. You might want to change this, and install the shunt as the first item from the battery, that way you'll be recording any power that the breaker consumes. Perhaps that is where your missing amp-hours escaped to... Cheers.
Exactly !
But didnt the same current that went through the breaker goes through the shunt?
Great breakdown ... one thing has me ... Building a powerwall is straight forward, I'd like to see an Automatic Transfer Switch for Grid to Battery power, I have a 200amp service, but the only ATS I can find seem to be 100amp, should I take the feed-in from the grid and split it one to a sub-panel powered by the ATS, separating out the circuits I want to power from Batteries?
I should add that when I got them, I hooked 18 of them in parallel and used my iCharger x8 to do a 1s charge to 3.65vdc. it took about 3-4 days, lol. it was awesome though.
18? are you super crazy? you should have used 5 chargers to charge that many cells
Good test. I wouldn’t be cut up about about 96.4% of the rated capacity since by your own admission there were heat losses (resistances) in your circuit that happen before the current shunt. Well done though and thanks for a good review.
Is this setup copatible with Growatt SPF 5000 ES?
Is it possible to charge the battery and use inverter with this bms at the same time ?
Yes, you can connect a charger and inverter at the same time. If load exceeds charger output, the battery will discharge. If load is less than charger output, the battery will charge.
Thank you
Great video. Out of curiosity how long does the heater last before battery is too low.
Thankyou
How long did it take to ship these cells and did you have to pay for shipping?
It took approximately 8 weeks from date of payment to date of delivery. And yes, had to pay for shipping.
I'm not sure why you would get a modified sine wave inverter. Also does it not matter that it is a 100a BMS and the batteries are capable of almost 3 times that. I'm curious because I plan on getting four of those cells, but I'll never use more than 100a so is it ok to use that BMS on those? I guess if it went over it would just trip? Not sure, sorry still new to this.
I suspect you are losing at least 3-5% of the battery power from Cables, BMS and Circuit breaker. I always try to double the ampacity of any device that passes the full current to the output. So in your case you would need bigger cables that are designed to handle at least 160 amps, probably 2 ga to 0/0 ga for that run length at that voltage. The BMS should be 150-200 amps rated. And at least a 150 amp fast trip circuit breaker. All these together should reduce your losses to heat generation in the components by up to 50 watts.
If you did a direct capacity test on the battery you would likely see just over rated capacity, with no hardware in between.
Keep up the good work, and Merry Christmas :)
Ciao grazie per i tuoi video sono davvero molto interessanti.
Ti volevo chiedere secondo te è meglio installare delle batterie LTO oppure delle batterie lifepo4?
Da quello che ho capito dal tuo video e dai tuoi commenti le batterie lifepo4 fanno una scarica di corrente limitata a max 0.3 C per non danneggiarle.
Ma soprattutto la temperatura esterna quanto deve essere per non rompere le batterie?
Spero tu mi risponda nel frattempo ti ringrazio. ☺️
The manufacturer doesn't recommend using those BMS products with anything more than 100ah last time I checked about a year ago. Has this changed? They don't have much balance power. 200ma total I think. Maybe that is for 16s, not sure but it would be nice if this was at leasts discussed.
So how long did the space heater actually run off the battery pack you made?
Hello. I have a question. I have a 250amp AliExpress battery plus his 250amp Daly BMS. When I'm charging, I have 14.1 out of the charger and in the BMS
But, out the BMS (P+) I only have the battery voltage 12.9. and it's not increasing
Am I not supposed to have 14.1 or more than the battery voltage out of the BMS? Thanks
Well done. Do you think two 12v configurations could be wired in parallel to work with an existing 12v system? Looking to replace a set of 12v AGM batteries.
Yes, you could wire two 12V in parallel. You will need 2 BMS that way though. I would first wire the cells in groupings of two (parallel) then wire those in series such that you only need one BMS (4s2p). As for replacing the AGM batteries - you will need to check that the device supports LiFePO4 batteries to prevent over charging/discharging.
@@LithiumSolar Thank you. I did not know about the 4s2p BMS. Any thoughts on detecting low temps to prohibit charging?
@@patrickmchargue7122 newer models of the Daly BMS like he used have low temperature cut off, but you have to ask for it when ordering. Newer models can also be purchased with Bluetooth and USB ports for monitoring and changing parameters, but again, you must specify when ordering.
@@john_in_phoenix Thank you.
what wires do you connect the charger to?
What's wrong by charge them in series? I replece the lead cells on a power back up with 4 blue cylindrical lifepo wired them in series without a BMS. till now work fine. They had outperform the original specs. Although they have not been fully charged at 100% the v out was 13.? not 14.4. Now I'm planning on buying 4 cells like these to replace my car battery.
thank you so much, I am planning to build a DIY power box using these 4 of these 280AH cell. Learning from your last video, i will need 4x280ah battery cells, 150A BMS, MPPT Charger, 2000 Pure sine inverter... how many fuses or breaker do i need for safety measure and where is best to put these fuses? Will i also need some kind of relay circuit device? what is the recommend wire sizes?