Help with the balancing part in jbd

[thedark]

My 12v 100ah battery bank not balancing or charging properly although I have tried couple of lithium compatible inverter still each cell charge to 3.4v with voltage difference of 0.01v but after that the difference increases significantly and one of the cell hit 3.65v and bms stop charging because of cell over voltage protection I have attached some files can someone help I'm new in lipo4 and unable to figure out the issue here

 

[MisterSandals]

charge to 3.4v with voltage difference of 0.01v but after that the difference increases significantly and one of the cell hit 3.65v and bms stop charging

You should see where 1 cell reaches about 3.5V or around there and notice the overall voltage. Set your chargers top charge voltage to this voltage and see how it goes. If it charges to completion then you're close. If you think the batteries aren't quite charged, set the absorption time a little longer.
Measure your voltages after your battery charges and rests in a half hour and check back in with the results.

 

[LakeHouse]

My 12v 100ah battery bank not balancing or charging properly although I have tried couple of lithium compatible inverter still each cell charge to 3.4v with voltage difference of 0.01v but after that the difference increases significantly and one of the cell hit 3.65v and bms stop charging because of cell over voltage protection I have attached some files can someone help I'm new in lipo4 and unable to figure out the issue here

The issue is that your cells are out of balance. You mention that they have very small voltage difference below 3.4V, and that is almost always the case even with imbalanced cells. Your cells are only balanced if they’re at the same voltage above about 3.45V.
Your JBD BMS has only very limited balancing capabilities, something like 150mA passive balance, so it’ll take forever for it to balance those cells. Some options to top balance:
1. Disassemble the pack and top balance with bench top power supply. Directions Here.
2. Install an active balancer.
3. Hold the charge voltage high enough (at least high enough that the top cell is above 3.5V) for long enough for the passive balancer to do its work and balance the pack. I don’t recommend this route, it might take weeks and would generally not be good for cell health.

 

[SupraSPL]

You can change the settings on the BMS so that it balances even when it's not charging, as long as the cell voltages are above 3.4. That way the BMS can sit and work on it overnight if the battery is not yet in service.

 

[MisterSandals]

1. Disassemble the pack and top balance with bench top power supply. Directions Here.

All these steps are sound advice. If my easy "adjust to make it work, or work well enough" aren't sufficient, these are the next steps you could take.

 

[shvm]

My 12v 100ah battery bank not balancing or charging properly although I have tried couple of lithium compatible inverter still each cell charge to 3.4v with voltage difference of 0.01v but after that the difference increases significantly and one of the cell hit 3.65v and bms stop charging because of cell over voltage protection I have attached some files can someone help I'm new in lipo4 and unable to figure out the issue here

A very common mistake I have seen newcomers make is that they directly target 3.65 V bulk/charge voltage. Don't do that.
One should always wait for the battery to come into balance first. And even after that it is not a good idea. At most you should be targeting 3.55 V/Cell instead. Most don't measure or calibrate BMS readout with multi-meter anyway.

Here is what I advise you to do:

1. Set Bulk/voltage to a safer value below 3.65V. Set float to a value at or below 3.37 V/Cell
2. Turn balancer off and let the battery get fully charged. Monitor current.
3. As soon as charging current starts decreasing and goes below 5 amps, turn the ChargeMOS off in your BMS.
4. Alternatively, If a Cell starts 'going above roof' and hits voltages above 3.6 V before others, turn off charging (Step 3)
5. Turn on the balancer and tweak the settings in such a way that balancing happens.
   Keep voltage deviation to minimum allowed, but decrease balance trigger voltage.
6. Let the voltages equalize. If solar runs out and your battery starts getting discharged, turn off the balance switch and DON'T FORGET to turn on the charging switch for tommorrow.
7. Wait again for battery to get fully charged to repeat Steps (Step 2 to 7) again.

With passive balancing it may take multiple days for cells to fully come into balance. Balance only after charging has finished as I have outlined above.