Noob question thread! 2020_Summer

[b264]

@abusfullofnuns

need help over here confirming I’m not crazy for suspecting a BMS issue.

You’re not crazy for suspecting that. But it doesn’t sound like a BMS problem

@abusfullofnuns

I have a d140 that is about 30 cycles old. It was plugged into @torqueboards 4A charger for the second time and I believe something let go. I fell asleep with it plugged in/charging and when I awoke it was less than 50V. Thought it was weird and went to check if it was plugged in. Light was green but voltage was down to below 49V.

I unplugged the bms and confirmed that all p-groups were charged to the same value, and the value is equal to the voltage measured through the charge port. I confirmed that there is continuity on the charge port + and - . Also have confirmed the ground is good for the BMS. I have also tried a second 1.5A charger.

Is there anything else that I could check or measure to confirm what went wrong?

@abusfullofnuns

I did not discharge at all. More to the story, though.

P-group voltage was all 4.08V exactly. Loop key was still in and metr/vx2/escapes all on drawing power. I assumed it had got to cut off voltage and not restarted when voltage dropped. It was 48.9 at last check when the charger would not kick on.

I just went to check voltage drop overnight. It was only around .2V. I decided to check the charger again and it’s working. I haven’t moved a single wire since last time I checked. Really stumped now. I could believe a bad solder joint, but it’s not even been breathed on since last check.

@abusfullofnuns

The 4A just charged up the last 1V and is fully charged and reading 50.4V.

Are you sure you aren’t just seeing the exact correct behavior for a float charger? I think you are expecting the outcome of using a trickle charger but actually have a float charger, which is usually better.

If you plug a fuel gauge into the charger (without an esk8 plugged in) and it jumps from OFF to 50.4V to OFF to 50.4V to OFF to 50.4V endlessly then you have a float charger. If it goes to 50.4V and stays there, then you have a trickle charger. So find this out first.