Can you charge LiFePO4 batteries with different capacities and SOC in parallel?
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- Опубликовано: 8 сен 2024
- 4 batteries in parallel, different capacities, different state of charges. What could possibly go wrong??? Well, maybe nothing if it is LiFePO4. We explore how these batteries react when we connect and charged them in parallel.
This test was, once again, requested from some of my viewers and in today's workshop, we will find out what is going to happen.
I prepared four 51V batteries with different SOC and connected them in parallel. I started charging this setup from solar as well as from my other large battery bank to increase the current. A bit too much at one stage but nothing serious happened!
We can see and explore why LiFePO4 is so easy to parallel and use. With the help of a sponge, I explain exactly what happens with these batteries and why LiFePO4 is safer and more forgiving than other chemistries.
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You know you've graduated from primary school to high school when you've watched Will Prowse and feel comfortable with all his content and start watching Off-Grid Garage and appreciate the depth of explanation of seriously complex concepts!
You’re in high school? I grew up in the wrong country 😂 Watching this as a mechanical engineering student and still some things go over my head..
You continue to explore the various characteristics of LifePo4 cells in a very scientific manner. There are lots of RUclips channels doing things with this chemistry but I am not aware of anyone doing all the things you have taught us about this specific chemistry.
I thank you, sir. I have learned so much from you.
Thanks a lot, my friend. I'm very happy to share all this with a great community.
You are by far the most thorough and logically detailed person online concerning solar stuff….I have learned a lot….thank you………..jim
Awesome, thank you!
Marvelous! Thank you very much for the lab experiments - so much appreciated! This is one reason why I went with LifeP04 from the start - and will actively discourage anyone from using plain Lithium batteries, especially since those are far more prone to dangerous activity.
Thank you. Yeah, LiFePO4 is pretty save and forgiving. Usually no high currents in these setups.
Thank you Andy for the comprehensive reviews and analysis of the topics. I'm a professional electrician, recently I've also been dealing with solar systems and your videos are of great help to me. Thanks and greetings from Bulgaria!
Great video Andy. I have 10 batteries now. I found using a buss bar vs parallel cables from one battery to another easier to ballance batteries. All JKBMS. Different AH batteries. Normal operation I stay around 80%. Maintenance now every week i take one battery one cell swap out for uohm testing and cell curve testing for my spread sheet. Even grade B cells operating fine. Thanks for your testing.
Thanks for sharing. Yeah, with 10 batteries in parallel, I would use a bus bar as well.
You test one cell every week? I thought I was nerdy... 😁
I always love those dramatic moments of flipping up the cirtuit breaker whatever I do as well :D Greetings from Slovakia
Even I check everything several times and take all the measurements, it's an exciting moment. Especially in such large systems.
Very interesting. I was waiting for the KABOOM 😂👍
i live in Kyiv, UA, KABOOM is our reality now for 2+ yrs so if all my battery pack blows up - nobody gives a shit ((
Love this oldman, cheers.
The comparison with the sponges is ingenious. Thanks for this video.
Kind regards from Germany.
Thankyou. I thought it would be easier to understand...
@@OffGridGarageAustralia Yes it is !!!
Great explanation Andy! This should clear up any confusion people have when buying or using different batteries! Great Job!!
Love the doing analogy and that commercial is one of my favorites of all time
Mr, Dumass! I didn't know it until I searched for it😂
@@OffGridGarageAustralia 😂
Its very reassuring to see a test done like this. Means you know that the batteries will cope.
Just as long as it doesn't have a full time running active balancer.
I'm thinking for mine of Seplos, with a Neey active balancer for the win.
You cannot go wrong with the NEEY!
That's exactly what I like about your canal - you show what happens when... I can confirm it exactly like that... I'm currently building my PV system and have 2x280Ah batteries. I had one at SOC 100% and the other at SOC 40%, the voltages were the same except for 0.01V, so I could connect them in parallel.
Unfortunately I'm currently missing the panels on the roof...😊
Thank you. Yeah, it's quite fascinating watching these batteries charge and discharge when they all have different capacities and also cable lengths.
I am from India..
,,,I am regularly watching your video..
Very interesting..❤
Thanks a lot and welcome!
❤
Thanks so much for this active demonstration. I have thought in my head for some time now that this is exactly what would happen. I currently have 6ea Valence U27-12xp batteries in parallel and have had zero problems on the boat. Most will state to only put 4 in series or parralel at any time, but my 6 have worked just fine. I have purchased another 7 of these batteries to add to the bank and it has been suggested I have different charge controllers. Nonsense I thought, and hooked the all to the same buss bar with verying length of wire. Of course I made sure all the wires had the same resistance (small short ones and long large ones) as when starting a very large diesel engine, I need in excess of 1000 amps and need that balance under this high load. Now with the 13 batteries each capable of 300 amps output for 30 seconds, that should give me almost 4000 amps for engine starting, easy even with different resistance cables as long as they are close. Thanks again for confirming what I always thought was the case.
Another great informative video from the best solar/battery guy on YT. Thanks Andy!
Thanks so much😊
Wish I could give two thumbs up on this - one for your normal, everyday, "It's 100 amps outside" :) and one for the "dumba$$" section. Well done. Love the channel!
Thanks, looks like my jakiper 100ah and my selfbuild 280ah will go play nicely together.
Excellent video Andy! Have held off connecting my original well used LiFePo battery with the new one I built from new cells. Time to hook them up!
Yes, get them connected!
I recently built a 2nd bank of 16 x 280Ah cells and put them in parallel to the existing 3 year old bank of 16 x 280Ah cells. I have found that the older bank discharges at a faster rate than the new bank. Old will drop ~32%, the new one will drop ~18% overnight. The older bank also charges at a faster rate. They both reach the Absorb voltage at roughly the same time though, and charge tapers off to
@@drdos6718 thanks for sharing, that is quite a large difference between your two banks. It can only be internal resistance being very different...
I experienced this exactely like that with my 6x16KWH 300AH packs
my packs have the Active balancers with voltage trigger set at 54.2 -53.5 works so nice...
Thank you for sharing this experiment. I understand much more about lithium iron oxide batteries.
Great, thank you for the feedback.
Cant wait to see the video of the Gobel Power with the Neeeee balancer. Have one with the 5A active balancer and a 2nd in order, waiting for shipping.
I have received the NEEY already, just need to find the time to start the project...
off grid garage - home of frankenstein battery and its relatives
great video
0:04 oh lord, I'm hungry now!
Same here...
Another Great hands-on test backed by fine science and engineering
Keep it up!
Thank you.
What a amazing Power storage, great
So good for testing. I can combine all sort of batteries and test it all out.
The best video showing that communication between the batteries and at least inverter doesn't matter anyway! Thank you very much! ❤
Inverters like to 'talk' to batteries, but it's not technically needed, although some inverters won't 'invert' if they can't 'see' the battery BMS data... No good reason for it...
I will parallel all batteries I have at some stage without any communication. As we have seen from the battery shelf long-term experiment, coms is not needed. The BMS take care of their individual battery just fine...
@@OffGridGarageAustralia im preaching this since I got it thanks to you experiments... No one is believing me without your proof videos... I guess now they see. Everybody is hardly trying to get the bms talking to their inverter and doesn't know why 😅
@@finfin82 Technically no, comms is not needed, in a very crude manner you can just set a "cutoff" voltage in the inverter..... But, my question then to you is. How do you know what the SOC of your battery is? Otherwise, what would set your very expensive home inverter system apart from a car battery and and a 12V inverter?.....
@@GapRecordingsNamibia well, do i need to know the SoC? it wouldnt change if i do? im reading the battery-stats with a small nmc and build my own grafana graphs, but actually when the bat is full enough it is used if not, its not... so what? all smart stuff like if the bat is full in morning and the day will give me sunshine i handle in nodered with readed stuff and having the option to suck the rest out of the battery... no inverter communication would help there either?!
Thank you so much for this .
Over the years I've asked a number of experts this exact question. All of whom have looked at me as if I'm insane for wanting to mix capacities (of the same chemistry) . "I wouldn't if i were you" is the usual response , with no justification or reasoning why this would be so bad . No evidence, nada , nothing .
You are the only person who has actually had the cojones to try , film and publish real world results .
As an adendum to this test/demonstration i would be curious if there would be any detrimental effects to each battery over an extended period ?
Thanks again Andy.
Fattrucker
Thank s for your feedback. There is no downside of paralleling different capacities with LiFePO4. The voltages are all the same and batteries will balance against each other when fully charged/discharged.
Hi Andy, I just love your channel and I have learned so much from your very detailed and no bs explanations. When you explain it in simple terms like you do that means that you know exactly what it is. I am so addicted to the stuff you do it makes me want to go out and buy batteries, Chinese test equipment and of course beer!
I am not sure if you will get notified of a question that I have regarding leaving LFP, or the Salty, sitting at 100% SOC all the time and possibly for months and maybe longer. This is a backup UPS and to be honest it is a good thng if we do not lose input power to the UPS because that means our power grid is performing well. Do you have any best practices on charging and discharging periodically for no reason other that to perhaps keep the cells from gettting too fat. LOL. Do they really need to be exercised?
Thank you my friend for all the information you pass to us. I rally appreciate it.
I’m missing something about that challenge with the active balancer. It stopped charging because one cell hit the 3.65 cutoff. Shouldn’t the active balancer drain off some of that energy and distribute it to the other cells? Lowering the voltage of that cell and allowing it to start charging again.
Depending on the charge cutoff the bms will stop charge at the max cell voltage. The highest cell will balance the lowest cell. When the highest cell voltage drops below the setpoint, the charge will turn on.
Thanks Andy, as usual a great description! Cheers
Thanks, Dave.
Thanks Andy
Wayne, thank you!
Great explanation, experimentation & analogy with Sponge Bob Andy, it was good to see this done with ur nice big battery setup, but no surprises here after watching ur old videos way back using the Palo cells & bigger batteries when u were in ur early testing phases & a bit of my own experimentation on this.
Like to see this again with ur Seplos setup, maybe try 30, 60, 90% SOC or a 10, 50, 90% SOC test & see how they vary. Love ur scientific approach & logic. Cheers
Thanks 👍
Yeah, I'll repeat the test at some stage. The current will increase slightly when we leave the flat part of the curve and go 10% or 90%. Still, it is not a drama as I have done this with my battery shelf several times. LFP for the win.
YESSS!! I love the sponge tests
Sponges are sexy!😂
Hi Andy. Please always connect parallel batteries diagonally. Meaning i.e. one lead on the negativ of the bottom battery and the other on the positiv of the top battery.
Then the currents actually tell you something.
Hang on a mo!!! Andy was that you I see burning a fossil fuel or was I still tripping???
You got your money's worth out of that sponge dear boy!
Luv ya
Gaz 🏴
Great demonstration!
Thank you. A very frequently asked question.
Very good as always, Andy!
Nice to see the same game with discharging. It's interesting to figure out if the lowest capacity battery will be blocked by bms or all the batteries come to the bottom line at the same time 😮, it's a miracle 🎉)). It's really interesting from the current distribution point of view. cheers 🍻
They will all get to charged or discharged state at the same time when in parallel...
Thank you.
Yeah, that's is what I observed as well, regardless the capacity, all batteries will come to the same high SOC or low SOC pretty much at the same time.
Very nice explanation with Spongebob 😅
Nice one Andy, thank you for sharing this experience🙏 I'm planning to mix at least two types of batteries and I'm glad to see, from your test, exactly what I would expect to see. My mix is going to be a little extreme as I have one 5.12Kvh and one just under 16kWh. PS) Yes, the Zketech 40A is a must and I'm glad to have it as part of my test equipment.
Thanks. That should be no problem connecting the 5.1kWh with the 16kWh battery. Exactly what I had here in the test.
Heya, because the flet charge curf of LiFiPo4 is differant then lion ( 18650 ) we have to charge differantly and LiFiPo4 holds lot's of high Ah you need an active balancer with some nice amp's balancing current but the active balancer only start balancing in the high end of the CC. that's what I have learned from all the test's that you have done. thanks for that and all the hours of enterteanment.
Groovy .. nice flick
Good info Andy, Thanks! It might be interesting to charge the Tesla using those packs at high discharge rate and see how well the discharge balance holds, as I've seen discharge imbalances when paralleling 300wah & 600wah LFE ebike packs, sometimes with one or another pack randomly cutting off on low voltage protection about 10% before the rest, and I suspect it may have something to do with charge imbalance that was not apparent.
Otherwise, The pretty much replicates what I've been observing parallel charging different capaticy LFE packs (300wah and 600wah). I've also been testing a single 300wah 48V Li-Ion pack Paralleled with 2 parallel 48V 300wah 32700 LFE (Lithium Iron Phospate) packs charging to 54.6,V and they balance charge very evenly. However, the lithium Ion pack does reach the same cut-off voltage before the LFE packs.
Presume the Tesla feed would need to go to AC first, thus inverter capacity would be the limiter... Fast charge Tesla is 480vdc so would need some battery reconfiguration...
@@dougle03 Andy has a 220v home charger for his Tesla and uses one of his Solar inverters to charge it, essentially using it as a load bank.
Yes, Tesla AC charging. I can do 16A AC charging (3.7kW max) with my setup.
The batteries should not shut down as they all come down to low voltage at the same time. Pretty much the same as we saw charging them, just the other way around.
Once one BMS shuts down, it goes quick and the others usually follow soon after.
In a good battery design, the Inverter should shut down before we get to such a low voltage so, the BMS are really your last resort.
Hi,
you are connecting and disconnecting a lot of batteries. Maybe using forklift battery connectors might ease your work. They are available as 80, 169, 320 and 640 amps as a standard.
Thanks for your great video!
BR Björn
Thank you, Bjoern. I will need to look at something better in the future, definitely. I have some upgrade to to for this area anyway. It is really just a temporary setup.
Great video Andy 👍
Thank you 😊
Hola, I would like to see this same test but with parralle brass bar each side of battery pack instead of cable from top to bottom. I love this show !
There is no way to do this with packs that do not have the same pole/ terminal spacing....... That is why he used cables.... if all the batteries are the same make and model this is doable, otherwise not.
What do you expect from brass connections instead of the cables I used?
Thanks for the lesson. 👍
Please! Nobel prize to Andy for sharing knowledge around the world!
Hahaha, thank you. I'm happy with a S.P.A.T. here and there 🍺
Great Test, I connected 6 Large Capacitors in parallel with 4x 18650 batteries to make 12v jumper battery. I hope it works!
Use 6 3000F super caps in series no batteries required.
@@universeisundernoobligatio3283...at great expense of course....
Energy needs to come from somewhere...@@universeisundernoobligatio3283
I have LTO batteries here someone send me. He had them as a 12V starter battery connected.
If LTO batteries were as cheap as Lipo4 batteries, I'd build big bank of them.
Excellent video Andy. Suggestion: Could you show the real time results with the same system, this time testing the impact on batteries with less capacity while connected to batteries with more capacity. What is the best approach to limiting the discharge on the smaller capacity batteries with this type of arrangement?
I have a video where I paralleled a 5Ah 12V battery with a 300Ah 12V battery and showed everything in real time. That may already help?
ruclips.net/video/fQz7vZEYLfY/видео.html
GsD hab ich grade nen Teller Gulash vor mir stehen beim starten des Videos🤣
I just have a plate of Gulash in front of me when starting the video 🤣
Nice, thanks for sharing 😁
On your way to a will in Las Vegas sized collection of battery backup!
Nice work.
love your work
Thank you!
21:18 I haven’t heard any comments regarding this high current to the third battery. Why is that?
Such an interesting analogy!
It's not 100% but roughly how it works.
Hah, watching for a 2nd time, when you go to the whiteboard you say, "Let's explain what's 😂currently😂 happening" 😂😂
very good. thank you!!!
It doesn't matter. Hello! From the Netherlands 😁
Hello! 👋
Very interesting. The question that comes to mind now is how the discharge SOC will be managed ? When discharging, the smaller batteries will discharge faster, as they have less charge stored. So how do you manage the batteries not going below 15% SOC, as the smaller ones will reach this before the larger batteries ? Can the BMS be configured to manage the cut-off SOC for each battery independently ?
All parallel batteries will discharge over the same time period, i'e their SOC will be aligned.
The batteries with the smaller capacity will discharge slower as they have a higher resistance than the ones with higher capacity.
Watch this video here with a 5Ah and 300Ah battery in parallel: ruclips.net/video/fQz7vZEYLfY/видео.html
Not the case, please don't reply if you are not qualified to answer the question.@@dougle03
Personally, SOC% is not important; what is important is the small voltage delta.
3:00 min 20% SOC, max 80% SOC... hmmm. well since these all have PACE BMS with charge current limit circuit, it is definitely OK to parallel them even when one of them is 100% SOC, while the others are at 0% - because there is a charge current limit circuit.
However those other BMSes in the battery 2.0 without charge current limit circuit, its gonna be xxxxx.
PS: Charge Current Limit and Over Current Protection circuits are not same. The latter stops charging when over current, the former limits the charge current when a threshold is reached.
The BMS will cut off charging if the current exceeds allowed, there is no moderation of the current by each BMS...
Yes, the Pace and Seplos BMS have current limiter, so it keeps them save. As we saw, there was only a mere 30A between the 80% and 20% battery.
However, I have done this a few times with my battery shelf as well and if the current gets too high, the BMS will simply disconnect the battery, wait a moment and tries again. It may do this a few times until the voltage has equalized and the current is below the protection settings.
Nice....
How about discharging of battery different amp? Many people set their inverter to cut off at 10% or 20% Soc to reserve their battery life cycle. Once we mix battery with different capacity the smaller one will go off 0% while the bigger one still provide power ...
Can you charge LiFePO4 batteries with different capacities and SOC in series?
No as the voltage curve would not match and you'd end up with horrendous cell imbalance...
Hi, you have a list of batteries and BMS you use... could you also link your tools e.g. the DC Clamp Amperemeter?
I think many of your viewers, including myself, have learned a lot from your videos. Yet many uninformed/uninterested people don't know the difference between the lithium iron phosphate cells and nickel manganese cobalt cells. They regard them as the same as they are both lithium and are wary of them because of the bad press li-ion has received.
You have a shed load (literally) of LifePO4 batteries and was wondering if you ever have concerns over safety? Other than doing something silly with them.
Yeah, both lithium but both very different.
No safety concerns, it's all very safe with the place locked when I'm not home. And it's like 60m away from the house, so...
Like# 397 - no notification again!
I have a 14s 100p 18650 setup, I would like to add 16s 1p 280AH. Put the 18650 in a steel box outside the shed and hope for the best. What would be your predictions? I would guess that the 280AH cells would discharge first and then the 18650 second as a backup? Lets see that experiment. LOL Ps Love all your videos.
Be very careful. I don't like different chemistries being matched with these batteries.
Looking at the different curves between Li-ion and LFP, my prediction would be that the Li-ion battery will follow the charge/discharge curve of the LFP battery. You will never fully charge the Li-ion battery and never fully discharge it either (unless you go really high and low with the voltage and wait for the LFP BMS to shut down).
Hi Andy, nice video (again). Suggestion for an experiment: how does parasitic resistence affect the load on 2 (identical) parallel batteries. E.g. 2 batteries in parrallel where 1 pack gets longer cables and/or additional connectors. My expectation is that the pack with the lowest parasitic resistence, will see the biggest load (= delta in SoC). But how much? Is it significant? Would it wear out one pack significantly faster than the other pack?
Yes, that's a good experiment as well. I have many batteries connected with different cable lengths and it is very interesting to watch what is happening during charging and discharging.
I'll put your suggestion on my list. Thanks.
So the TL;DR is if you want to add a second or more batteries to your existing system it doesn't matter the current state of charge, they will eventually balance out
Maaate. I like your vids and your style.😁
👍
Great
Hi Sir, for the Gobel battery which had an OVP, is the capacity truly 100% or did it jump from a certain percentage (say 85%) to 100% when it hit the OVP? Thus the 292 AH reading isn't accurate anymore?
Seems the 1st battery has reduced it's capacity, though it shows SOC as 100%, FCC and RM shows 91.7 AH. Looks like BMS prob to me.
That's just a calculation of the BMS. It has nothing to do with the real SOH. I have done a lot of testing with these batteries and BMS including disconnecting the BMS sot he calculation is off until they are calibrated again.
They should not show this number anywhere as people may freak out 😉
Does this means I can connect my two batteries 200Ah and 100Ah in parallel and use them as one 300Ah battery permanently? I wanted to try, but wouldn't like to damage something..
Exactly correct. Enjoy your growing power bank :)
Makes sure every battery has its own BMS and circuit breaker. They also need to have the same voltage, cell count and chemistry. Example, 51.2V, 16s, LiFePO4
Based on your testing, which BMS do you recommend as the most stable/durable for a hybrid system. (S16-2P, 100A)
I have been testing Daly (with Daly active load balancer and parallel board. The Calls are 138Ah BYD blade cells. Set up is S16-2p. 2 battery packs in parallel. the BMSs work well for a few months but then start losing connecting with one or more cells, showing those particular cell"s" at lower voltage than they real are, Which in turn end up damaging the cell"s".
The new JK-BMS is just at the doorstep, so probably wait for the test results. That would get my recommendation.
Thank a lot for this video i have learn so much. I have a question about lithium battery. I have dev a pcb for a gps tracking that auto cut off when power goes down and switch to battery witch are 2 lithium cell in parralell can i add a passive balancer to each cell
Can you do this with different BMS example a Pace and a Seplos?
With all that free power from the sun you could use a induction cooktop to cook your eggs
I'm in the process of replacing the BBQ with an electric one.
❤
Hi Andy, I would like to ask you for advice, I have a 200ah Victron battery on my camper, I would like to add a second battery but the Victron battery is very expensive, according to your tests can I add a different battery by placing it in parallel? Thank you
Yes, you can parallel any battery with the same voltage and cell chemistry as long as all BMS have their own individual BMS.
Thanks Andy. Will an active balancer that is always on unbalance the battery if the battery is sitting for weeks at full state of charge?
Not at full SOC, no. This is the time to balance so that's not causing any issues. the problem is when the cells go back in the flat part of the curves and you would balance there, so below 3.35V. This causes the problems if the balancer is on.
But, you should not leave the battery fully charged for several weeks. That's really unhealthy.
LifePo4 is one of many Lithium Ion chemistries. You're probably just referring to other more volatile Lithium chemistries? such as NMC or NCA?
Haven't we already done a test like this?
No, not on this channel. And even if so, there are always new viewers ...
What bms do you recommend with lifepo? Have a griwatt 12kw off grid split phase inverter and a 16s 2 parrell 3.2-48v lifepo pack, having lots of trouble keeping the cells balanced
Great test, would it make any difference if you connect the charging cables diagonal. Positive on bottom battery and negitive on the top battery ? That is the way that Victron recommends connecting parallel batteries.
That would become a series connection, and the voltage will increase. 51.2+51.2 = 102.4V
@@furyjk98, I think Douglas means that the top pack sees more parasitic resistence of the cables than the bottom packs. By connecting e.g. the positive to the top pack and the negative to the bottom pack (= diagonal), the parasitic resistence is more evenly spread across the packs.
Thanks you are correct and you understands what I was trying to explain,@@ThePetervangils
I have my battery shelf just connected from the top and did not run the negative cable all the way down just to connect it to the busbar there.
I have also done the same with the Seplos Polo batteries and the aluminium busbar I installed at the back. I feed this form the top.
Theoretically, the top battery sees a bit of a higher voltage while charging and a lower voltage while discharging than the other batteries. From my experience this difference is so small though that it would not matter much.
In larger installations (maybe 6+ batteries in parallel) and much higher charge and discharge currents I would connected them across as well.
Does this video mean thatt its not necessary for me to balance my lifepo4 cells with a power supply before connecting them to my overkill brand bms?
You should still top balance your single cells to ensure they run optimally as a pack.
As I have said many times before. No issues or spikes what so ever.
Can you connect LTO with LFP in parallel?
you have them daisy chained in parallel. In theory is it ecaxtly the same if they are in parallel via centralised busbar? same results?
I can't wait to see the internet engineers comments....
I'm here for the comments! 😂
Will this work if you don’t have batteries with BMS’s that can be set at a certain cutoff charge?
The Neey balancer has two problems:
1.) You always need 48V as a supply voltage, even if you only have a 24V battery. Where should I get 48V from?
2.) The Neey Balancer must always be reactivated via the APP after a supply voltage failure. This is annoying and is often forgotten.
Why didn't you start with a larger voltage difference?
Does discharging work similarly in reverse, i.e., taking from the higher capacity battery until the Ah of all batteries reach the same Ah then discharges from all batteries equally?
Yes, it works exactly the same just in reverse.
@@OffGridGarageAustralia Thanks, Andy.
Is it possible also paralel blue cells baterie lifepo?
I have the seplos 2a active balancer on the way. do you have any plans to do video on it? also are all the 16s connectors interchangable between active balancers? so for example could the wire harness (from gobelpower) fit the neey balancer? so you dwouldnt thave to take apart the battery to change balancer
I have 3 old traction lead gel batteries (in sum 1000 ah, 1000 kg, today usable 25%) in parallel with 1 year old lifepo (460 ah) battery... of course with own bms... absolutely no problem, because the voltages are not that different. Surely main work is done by Lithium, only in lower voltage lead has to do a little bit more, but still less than the new battery. So the old leads can gently retire.
Nice, yeah, that's pretty much how you can still get some use out of the olds LA batteries until they are done. Is this on a 12V setup? I would imaging the voltage differences here are the smallest. 24V or even 48V, LA and LFP have a higher voltage difference.
@@OffGridGarageAustralia ... it's a 24V System. Bulk loading is until 27.6 V and the LA (with 12 cells per battery) with that are even almost full. Every few weeks I load completly full (with a handful of Amps) till 28.6V and the Lithium BMS (JK) is shutting down at 27.6V and only balancing... on the other side under 24V the Lithium is shutting down and the leads can do a little bit longer... these conditions (under 24 or over 27.6) are in practice not that often, so both systems are mostly physicly married ;-) ... in portion of work (or Amps) I would say 20-30% lead and 70-80% Lithium.
Dein Kanal ist spitze und du machst das alles total sympathisch... Gruß aus dem Kölner Raum :-)
@@detlefk.5126 Thanks for sharing, that is very interesting!
Thanks for your kind feedback and hello to Kölle!
question..
because both of the terminals are connected to the bottom shelf.. wouldnt that mean that there is a greater load on it. it would be getting worn faster?
wouldlnt it be better to connect the postive to the bottom battery and the negative to the top battery? spread the load? or am I seeing this wrong?
Imma follow this question, because I also have this exact same connection where my battery capacities are different. I want to make sure I connected it right too. Will it be better to have the positive line connected at the larger capacity battery or just the same?
Super my buddy
🥈silver for you