do you use fuses on each balance lead coming from the BMS to each cell?Yes, I am using the same harness. I will order or make a new one to check that, but the third BMS is working fine on that same harness.
do you use fuses on each balance lead coming from the BMS to each cell?Yes, I am using the same harness. I will order or make a new one to check that, but the third BMS is working fine on that same harness.
No.do you use fuses on each balance lead coming from the BMS to each cell?
it might help to install some. if there is some sort of cell surge on the balance lead it would help protect the BMS if thats the issue? also might help with diagnostics if you are blowing fuses on that suspect cell 9?
Sounds good, I'll work on that when I get the stuff to build a new harness, or buy one. Soon!it might help to install some. if there is some sort of cell surge on the balance lead it would help protect the BMS if thats the issue? also might help with diagnostics if you are blowing fuses on that suspect cell 9?
I also noticed when I was running the full 2A balance that there were occasions where the balance current exceeded it by as much as 0.4A.
There are two blown resistors (one of them shown in the picture) that correspond to the non-detected cells. These are 0.01R resistors on the input of the balance leads, before the mosfets. I think these are used here as a fuse, so it did it's job
Yes, its' failure mode is to short circuit the gate to the drain, so it's prudent to have some sort of 'fuse' here. Most car audio amps have the exact same protection.
Interested to hear your outcome with this, most likely a failed mosfet. I have unit on the bench to repair as well.
How are things going? My third BMS is still working with the reduced balancing current.Mosfets are the first thing I tested and they're all good.
How are things going?
Can I replace that single cell?
I set it to 3.45V. I had it there originally, but things were failing so I tried a lower balance. It didn't help, so we are back to 3.45V. We'll see. I may have to improve my soldering skills. I have many multimeters. Power supply went bad, but at the moment I am charging the battery using the BMS you returned and it looks good for now.Yes - you can. Did you set the balancing start voltage to something higher than 3V (i.e., 3.45V or something)? It's not normal for those resistors to fail like that (they act as fuses, but still). Anything special about cell 9? What is its rest voltage? Do you have a multimeter and a power supply?