Cuts out under load, 52v battery shows 57v fully charged.

[WheezyRider]

I've had weird values out of a BMS before when there was a poor connection between one of the sense wires and the BMS. When the pack was squeezed, the output voltage from the BMS read anything from 4V or so to the full battery voltage. Make sure your sense wire connections to the BMS are good.

 

[Paulpmpmpm]

The wire that was attached to the pad marked B- is the negative wire that's attached to the cell-pack at the other end.

7 tests to do. this shows the probe positions:
View attachment 38942

Thanks for replying.

I test from the thick black wire that attaches to the cell pack to the positive output and only get 52v its losing the volts through the bms somewhere im sure im just going to order a new one and replace it then check it again.

 

[vfr400]

Thanks for replying.

I test from the thick black wire that attaches to the cell pack to the positive output and only get 52v its losing the volts through the bms somewhere im sure im just going to order a new one and replace it then check it again.

Do all 7 tests.

 

[Paulpmpmpm]

7 tests to do. this shows the probe positions:
View attachment 38942

Hey I fitted a new BMS and still have same problem so I will do the 7 tests as you originally told me to.

I was reluctant at first because I really don't understand what I'm looking at with that diagram.

I really don't want to bother you but is there any simpler way I can understand?

Am I supposed to hold 1 prong at 1a and the other at the other 1a, then 2a and 2a ogether ? Etc.

 

[Paulpmpmpm]

Here are some pictures.

Positive end :

http://imgur.com/IXY0dp9

Negative end :

http://imgur.com/rvkQBBm

Output :

http://imgur.com/IlrdYUy

Output 2 : https://i.ibb.co/FbQH71Q/IMG-20201123-162215.jpg

 

[vfr400]

Am I supposed to hold 1 prong at 1a and the other at the other 1a, then 2a and 2a ogether ? Etc.

Yes.