Jackery Explorer 500 BMS identify/replace

[Sandman614]

Can anyone help identify the BMS in this Jackery Explorer 500 or a replacment. I've searched the part numbers on the board and browsed the usual suspects and haven't been able to find anything. For reference the part number: HTE042_BMS_P2, date: 2020-04-10, MARK2, chip part number: D502BB 507

Problem:
My friend ran the unit below 10% (big no no, according to Jackery), charged it with the AC plug and "it won't hold a charge" or "it will only work while plugged in". When I inspected it one cell was severely out of balance (1.88v) while the rest were moderately out of balance(3.83v - 4.08v).

Fix 1:
I balanced the cells with an active capacitive balancer. The severely out of balance cell is at 3.81v while the rest of the pack is at 3.83v.

Problem 2:
Same as Problem 1, it seems like the BMS isn't turning on it's output.

Fix 2:
New BMS with Balancing and Under Volage protection

Conclusion:
Jackery cheaped out on the BMS, no good Under Voltage protection or Balancing

 

[Techman Solar]

Have you emailed Jackery re the BMS? Perhaps they can shed some light on a) the BMS and b) how to resolve the issue at hand.

Techman

 

[Ken_C]

I just replaced the batteries in my Explorer 300. the cells were shot, showing negative voltage and what not. after replacing the cells and taking it from 4s9p with 2600mah cells to 4s10p with 3500mah cells, the BMS wouldn't turn on. I did some troubleshooting, and as it turns out. the 45a fuse on the BMS had popped. the previous owner had discharged it to 0 and beyond, who knows, but I replaced that fuse and it works again. the pic of the whole pack is when I was troubleshooting why the BMS wouldn't turn on. the symptoms before replacing the fuse was, the unit would turn on while it was plugged in, but wouldn't charge. check the mains lead coming off the pack to see if there is voltage, mine was showing zero volts out. the end result is I went from about 288wh to about 590wh, the thing lasts forever now.

 

[Ken_C]

Also noticed in your pics, the switch is in the off position.

 

[ve4edj]

I just replaced the batteries in my Explorer 300. the cells were shot, showing negative voltage and what not. after replacing the cells and taking it from 4s9p with 2600mah cells to 4s10p with 3500mah cells, the BMS wouldn't turn on. I did some troubleshooting, and as it turns out. the 45a fuse on the BMS had popped. the previous owner had discharged it to 0 and beyond, who knows, but I replaced that fuse and it works again. the pic of the whole pack is when I was troubleshooting why the BMS wouldn't turn on. the symptoms before replacing the fuse was, the unit would turn on while it was plugged in, but wouldn't charge. check the mains lead coming off the pack to see if there is voltage, mine was showing zero volts out. the end result is I went from about 288wh to about 590wh, the thing lasts forever now.

What cells did you use? I'd be interested in doing this on my unit as well. It's been shutting down at 25-30% remaining capacity and just generally doesn't have the capacity I need even if it ran down to 0.