Dead BMS

So for the past few days I had been seeing strange readings for the cell voltages on the BMS app. Sometimes a cell would have a very high voltage out of nowhere. I thought it was a problem with the app so I ignored it.

Today, when charging with my Mppt suddenly the BMS would trip from low cell voltage or high cell voltage (or both) and the voltages of the cells were all over the place. The strange thing is that when there was no charge, the voltages were more normal (still a bit off but not tripping)

Upon inspection with a multimeter I confirm that this is not the case (reading from the cells directly). So I disconnect the cell leads harness from the BMS, at which point the BMS shut down and so did the loads that were on at that moment.

When checking the voltages from the harness I realize one of the pins doesn’t read anything- the connection to the cell is a bit glitchy. So I fix the balance leads and put everything back together, but now my BMS won’t turn on. I have shorted the terminals like you are supposed to but it is just dead.

I am in the middle of a roadtrip and really need to fix this ASAP. Thankfully I have shore power now but not for long.

Is my BMS dead? Why though? Because I disconnected the harness while loaded?

The BMS in question is a Smart DALY 12v 4s 150A with BT and fan

ruiz.manuel94 said:

When checking the voltages from the harness I realize one of the pins doesn’t read anything

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This is what tells the BMS to shut down (it’s working correctly).
You need to get your harness working.

MisterSandals said:

This is what tells the BMS to shut down (it’s working correctly).
You need to get your harness working.

Click to expand...

But I have fixed it! All readings from the harness are what they should be

Ah ok. This is a known thing. I think this is the thread (search restart Daly BMS):