Hi-new eve 280 cells (8s) - first time charging in series to save time for top balancing. when the charger is on, the app always indicates one cell in red, -higher voltage by up to 60mv, but it's a different cell after i pause the charging and restart it (although usually one of two cells only). when i turn off the charger, all 8 are within 2 mv of each other. when i turn the charger back on the app will light up one cell. now that the voltage is over 3.4 on that cell, it is being "balanced". is it normal that they are very close with the charger off and instantly farther apart with the charger on?? it seems they were top balanced by the seller already (right?, assuming they stay as close as they are over 3.4v, or is it really 3.5v to see a difference??) i'm using the android version 3.1.1026
xiaoxiang/JBD balancing questions
- Thread starter chemosabe
- Start date
sunshine_eggo
Happy Breffast!
Equal voltages in the operating range (<3.4V) don't relate to "balance."
"Balance" refers to state of charge. Top balancing puts all cells at 100% SoC so that when they are recharged, they all land at 100% at the same time.
I believe red indicates the highest cell that's being balanced. If your two high cells are very close in SoC, they may change positions.
Set for:
Balance during charge only
3.40V and higher
20mV difference.
What you are observing is normal for unbalanced cells.
"Balance" refers to state of charge. Top balancing puts all cells at 100% SoC so that when they are recharged, they all land at 100% at the same time.
I believe red indicates the highest cell that's being balanced. If your two high cells are very close in SoC, they may change positions.
Set for:
Balance during charge only
3.40V and higher
20mV difference.
What you are observing is normal for unbalanced cells.
FilterGuy
Solar Engineering Consultant - EG4 and Consumers
What you describe sounds normal. Cells will quickly revert back to a resting voltage after charging stops. In the middle of the charging curve, the resting voltage is going to be close to the same for all of the cells.
Just let it keep charging till the BMS shuts down with a cell high voltage. If the difference in voltage right before the BMS shuts down is less than 30 or 40mv, I would be tempted to call it good and not bother with top balancing.
Just let it keep charging till the BMS shuts down with a cell high voltage. If the difference in voltage right before the BMS shuts down is less than 30 or 40mv, I would be tempted to call it good and not bother with top balancing.
You can also manually bleed off the high cell(s) with a 12V headlight bulb. At high-knee one or more cells may reach full capacity before the others and the voltage will spike up. You can actively bleed off those high cells to match the others. Assisting the bms balancer will bring them into balance more quickly.
I made this up this bleeder and top-balance all my cells in place/use - they're all very close now, and for sure once charging terminates. I don't charge with more than 14.1V, so my bms doesn't terminate charging for cell over-volt. JBD BMS with Eve 230A cells, 4S. Over the middle of both charge and discharge they'll stay within 3mV of each other. They will still go out 40mV or so at the very top of charging, and bms is balancing them.
I made this up this bleeder and top-balance all my cells in place/use - they're all very close now, and for sure once charging terminates. I don't charge with more than 14.1V, so my bms doesn't terminate charging for cell over-volt. JBD BMS with Eve 230A cells, 4S. Over the middle of both charge and discharge they'll stay within 3mV of each other. They will still go out 40mV or so at the very top of charging, and bms is balancing them.
