Troubleshoot Battery

[Johnrobert999]

I just bought a $20, 6-year-old Panasonic battery.

I checked with a multimeter, nothing on output, the charging cable input on the BMS I get 54 V
I would like to check each cell group. The only battery I repaired before the batteries were at right angles to this one so it was a lot easier as I could see the sides
last time I unplugged the 14-pin socket and put a pin in each hole to get voltage. I can see where each wire comes from the battery, not sure where to measure the other side.
I think the battery is ok since I get 54 V, and it's a bad BMS I once changed a BMS, and the 14 pin socket was the same so easy job
I would greatly appreciate any steps to test the battery.

 

[docw009]

The battery is three sections of 3x5 for 45 cells, and there are 7 cells in a 2x4 section under the BMS. That's 52 cells which makes sense for a 13S x 4P battery, The cell arrangement is sure odd though.

You should still be able to get the voltages off the BMS connector. How many wires are in it? Is it 13 or 14? If it's not 14, then it has left out B0 or B14. WHat does it say in the picture of the connector? I see a B-something.

 

[Johnrobert999]

I connected the charger end 54V to bike on full throttle it cuts out but when battery gets warm it does not do it as much
I ordered a new 13S BMS, see what happens when installed, last time I installed BMS I used all wires it came with not realizing old 14 wire plug was same, I could have switched plugs on new BMS, saving all the soldering.

Thanks for the reply

 

[docw009]

How did the cell voltages check out. Balanced or not?

 

[Johnrobert999]

I connected a good battery to bike to compare had more power could this be because other battery connected to charger port with no BMS
not sure what you mean by cell voltage , cheap battery 54v at charging port nothing on output port.

$20 battery unknown quantity it was local and cheap, something to play around with and learn.
it was already removed from housing and messed with, I thought 54v great it must be good, but not necessarily.

Could be some of the cells are bad because of configuration, I would have to tear it all apart and test cells.
He said it was 6 years old, but not been used much.