JBD BMS discharge issue

[L0veless]

yesterday I changed out the Jumper cable to a larger gauge with smaller lug holes. before this all cells were withing .001 for capacity.
After changing the cable cell 8 read out dropped from 3.42 to 2.844. which is the cell the cable is attached to Lower right hand cell in the a picture.
can I disconnect the 2 bus bars, disconnect main ground cable and the BMS lead for that cell and manually charge it as I have another dc charger that I use to top balance. to bring it up to the other cells? then reconnect everything and bring battery up to full charge? or do I have to remove all the BMS leads? my mistake when building this was that I cant get to the wire harness where it connects the the BMS with out pulling everything out.

Thank you

 

[L0veless]

as another note the cell that was fluctuating (9) in capacity has leveled out.

 

[TomC4306]

yesterday I changed out the Jumper cable to a larger gauge with smaller lug holes. before this all cells were withing .001 for capacity.
After changing the cable cell 8 read out dropped from 3.42 to 2.844. which is the cell the cable is attached to Lower right hand cell in the a picture.
can I disconnect the 2 bus bars, disconnect main ground cable and the BMS lead for that cell and manually charge it as I have another dc charger that I use to top balance. to bring it up to the other cells? then reconnect everything and bring battery up to full charge? or do I have to remove all the BMS leads? my mistake when building this was that I cant get to the wire harness where it connects the the BMS with out pulling everything out.

Thank you

No need to disassemble. Apply your power supply 3.65 or 3.7 volts to that individual cells terminals. Carefully observing polarity. Power supply red to cell black. Watch cell voltages on your BMS app. With that disparity, it will be hooked up for a while.

 

[TomC4306]

as another note the cell that was fluctuating (9) in capacity has leveled out.

Right, the two cells adjacent to that cable.

 

[L0veless]

Thank you

 

[L0veless]

At a complete loss now, I have ordered a Daly BMS hoping that will fix this issue.
cell 8 shows 3.024, cell 7 shows 3.654 cell 9 shows 3.337 my multi-meter shows all cells at 3.33. I disconnected cell 8 to change lead, when I disconnected cell 8, cell 7 showed 3.332 and cell 9 jumped to 5.003. reconnected cell 7 with new terminal and everything went back to 3.024, 3.654 and 3.327. I attached screen shots.
I purchased another Charger just for Lipo4 batteries 58.4 v 10 amp charger it ran for 10 minutes and it shut down. BMS reads full and turns off with 53.7 volts shows 100% SOC.
any advise would be greatly appreciated.

 

[PRBull]

I am having a similar issue in my solar system using 2 JBD Smart BMS (200A) in parallel to make a 16s 30kwh battery (280ah cells). When grid and solar panels are off and load goes over 5,000W, both BMS go suddenly to 14% SOC and RM capacity also change from over 200ah to thirty something ah. Then it continues discharging to near 10% SOC and them the BMS trips the whole battery. I have written to JBD support a lot of times with no success, they are useless.

 

[Bob B]

I am having a similar issue in my solar system using 2 JBD Smart BMS (200A) in parallel to make a 16s 30kwh battery (280ah cells). When grid and solar panels are off and load goes over 5,000W, both BMS go suddenly to 14% SOC and RM capacity also change from over 200ah to thirty something ah. Then it continues discharging to near 10% SOC and them the BMS trips the whole battery. I have written to JBD support a lot of times with no success, they are useless.

Sounds like you haven't reached the charge threshold to trigger coulomb counting.

 

[PRBull]

Sounds like you haven't reached the charge threshold to trigger coulomb counting.

I think it already did it, because original FCC was set to 280Ah (as per batteries specs...) and after several discharges it fixed to 252Ah, but I am not shure. The battery works find under easy loads, the RM trips only when is under heavy loads and some cells went down to less than undervoltage protection setting, is what I have noticed.