I need battery bank repair advice

[Paintedsky]

Hello everyone!......I have 64 of the EVE 280ah 3.2 volt batteries configured into four 16S - 48 volt battery banks.....These banks are connected in parallel, and feed into a 12kw Growatt charger/inverter. I am using a Overkill solar BMS unit on each of the four 16S banks so that every cell has a lead going to a BMS.........I need to replace one bad battery in one of the 16S banks with a new one.......what would be a good way to go about this?.......Thanks!

 

[Tooth Fairy]

Can you isolate each 48v battery independently?

 

[Paintedsky]

Yes, I can isolate each of the four 48 volt banks independently.....So I can disconnect the bank with the bad cell from the other 3 battery banks

 

[Tooth Fairy]

Yep.

 

[Paintedsky]

Should I redo a top balance on the repaired battery bank before putting it back in parallel with the other 3 battery banks?

 

[MisterSandals]

battery in one of the 16S banks with a new one.

First let’s get terms right so we can communicate. You have 64 cells. You have 4 16S batteries. The batteries are combined in parallel to form 1 battery bank.

Turn off all the loads, charging sources and remove all your jewelry.

 

[Tooth Fairy]

Turn off all the loads, charging sources and remove all your jewelry.

But leave your hat on.......

 

[TorC]

If you can shut down the whole system, remove it the string with the bad cell, get the new cell to the same SoC state, and put it back together before reconnecting everything, that's probably easiest.

Practical, as long as you have a switch for each pack, is disconnect the bad pack, top balance, reconnect, and flip the switch when SoC matches. Probably easiest to have the repaired string fully charged and flip the switch a bit after the rest of the bank goes into float.

 

[Paintedsky]

If you can shut down the whole system, remove it the string with the bad cell, get the new cell to the same SoC state, and put it back together before reconnecting everything, that's probably easiest.

Practical, as long as you have a switch for each pack, is disconnect the bad pack, top balance, reconnect, and flip the switch when SoC matches. Probably easiest to have the repaired string fully charged and flip the switch a bit after the rest of the bank goes into float.

This goes along with what I am thinking........Thanks!

 

[Capt Bill]

Make Sure your BMS is OFF before removing any BMS loom wires to battery terminal connections. I have also been unplugging the loom from the BMS when I remove any of those wire. The Reason was highlighted for me in a Mistake Lesson, then Forum Feedback. I once disconnected one BMS wire from a battery terminal when the BMS was active, and got a big spark. I then learned that kind of mistake usually frys BMSs. In my case, my BMS still worked, but I replace it because it's cell voltage readings were no longer accurate.

 

[Paintedsky]

Make Sure your BMS is OFF before removing any BMS loom wires to battery terminal connections. I have also been unplugging the loom from the BMS when I remove any of those wire. The Reason was highlighted for me in a Mistake Lesson, then Forum Feedback. I once disconnected one BMS wire from a battery terminal when the BMS was active, and got a big spark. I then learned that kind of mistake usually frys BMSs. In my case, my BMS still worked, but I replace it because it's cell voltage readings were no longer accurate.

Thank You!