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16s 48v 100ah

Kalinkoland

New Member
Joined
Sep 13, 2021
Messages
6
Hi Diy solar forum,

I have made a 16s 48V 100ah battery with a DALY 100a BMS. All cells are balanced and working, but when I use them, at some point cell 15 and 16 start to drift off quite badly. I have swapped the cells two times and it is not a problem with the cells.

The cells I have used is GFB grade A 3.2V 100ah

Have anybody else experienced similar problem or know what the issue might be?

Hope you can help me :)

IMG_71541.JPG
 
Have you checked cell voltage with a volt meter to verify bms is reading the voltage correctly? Are all bms leads the same length?
 
Check and redo balancing lead connections.

What to the cell terminal voltages read compared to the BMS?
 
Connection problem, wire length problem, or, bms problem. My guesses.
 
Thank you all, for the fast reply.

Balance wires are all the same length and cells match on voltage on the BMS. Shall I try to swap out the BMS? Or is there anything I can try to do first?
 
Well if all wires and connections are good and the problem is still on 15 16 with different cells I would think the bms is your problem.. not a big fan of the daly. With you only needing a 100 amp bms you might want to consider a jbd. Not sure where you are located but I do have a couple jbd 100 amp 48v 16s in stock..
 
Or is there anything I can try to do first?
Have you tried measuring voltages on the balance wire connector that plugs into the BMS?

Pin 1 is negative. Test against pin 2, should be ~3.2V. Pin 3 ~ 6.4V… increasing by about 3.2V (your cell voltages) across the connector.
 
If you swapped the cells around and the problem stayed with the same location, you have isolated the problem to either a bad connection problem .... or a problem with the BMS reading the voltage incorrectly.

Since the problem seems to vary depending on whether there is a load or not .... I would tend more toward thinking you may have a problem with bus bar connections.

In order to isolate the problem you need to do some of the voltage readings with a DMV that have been suggested.
 
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