diy solar

diy solar

Replacing 1 cell on a 4 cell 280Ah set

Mister Mike

New Member
May 29, 2021
I purchased and received on 11/21 new 280Ah (4 cells) from Alibaba. I had a tech out to figure out as soon as the sun goes down my system stops working. While trying to trace the problem a spark came out of the positive terminal on the 2nd cell closest to the positive input cable. He said he’s 90% sure that the battery is the problem.
I ordered a 100Ah $329 lithium from Amazon which will arrive in a few days.
If I replaced that single cell that is supposed to be the culprit with a new single cell would this present a problem?
I was thinking of getting one of the below cells. Thanks, Mike

3.2V 280Ah EVE280k Grade A Lifepo4 Battery Cells Produced in 2022 for Solar Energy DIY​

stars, based on ( 0 ) review
$159.99 piece
Do you just have a bad connection check the buss bars for corrosion or loosening what are the individual cell voltages
I am not sure I understand if the OP is replacing a cell or the whole battery. There is a big difference between a 280 Ahr cell and a 100 Ahr battery.
I am not sure I understand if the OP is replacing a cell or the whole battery. There is a big difference between a 280 Ahr cell and a 100 Ahr battery.
I ordered a 100Ah complete battery to replace the entire 280 Ah set.
You still may be able to get the 280 set working if you can diagnose the issue with that one cell or it's connection.
The connections are clean and I’m getting 3.2v out of that one cell. 13v out of all 4 of them until
I found some articles on how to cycle that one cell to check its capacity. I’ll let you know if I make progress. Thanks
Why are you using the aux connection from the mppt? I'm confused.
Are you sure you don't have a setting incorrect on the inverter that's using solar only?
Do you have voltage at the battery terminals after the sun goes down? Can you post actual photos of the set up?
The shunt should have nothing to do with it...
I’ll check all that. Everything works fine in the sun or with the vehicle running and then stops working about 5 minutes after sunset until sunrise and it all works again. If anyone truly know how to fix this I’m prepared to run about 500 mile round trip from Nashville Tn. for help. The tech thought it may be the shunt at first. I already dropped $350 for him to look at it and about $350 for the 100Ah one coming from Amazon and those 280Ah batteries may well be okay. I did the entire build myself except for the power. I just don’t get it and I’d rather not throw parts at it hoping I get it right. Anyway, that’s all I have in me for today. Thank you very much. MikeView attachment 141160
I’m looking into all your questions. Thank you, it would be nice if it was just a misconfigured setting.
Hi All, Great news! It’s working.

Regarding the last questions: The installer answered:
"Aux is the house battery connection for that charger.
The inverter doesn't choose charging source, the charger does. The only setting is battery type."

Although the system hasn’t been installed for long and only on one trip it appears it was a bad busbar connection as far as I can tell. I disconnected the positive and negative terminals and a couple busbars off and put it back together and it’s been working so far.

Since these connections are so sensitive I thought I’d upgrade to the best available busbars and terminal screws and washer. If you know what and where to purchase them please let me know or I’ll dig through the forum for those answers.

Do I need to do anything further like balancing them or any other suggestions to keep this working?

Thanks very much, such a simple solution to something that has been such a headache.


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