First time I removed all batteries I didn’t know about the problem. I think 80% luck and 20% precaution removing the BATLEFT & BATRIGHT connectors. After reading some posts and knowing the problem, while still removing the BATLEFT & BATRIGHT connectors I took them out with more care 
. Isolating the contacts with heat-shrink is the best solution (the 3D printed separator is nice but not as effective) because if the blue isolator/heat-shrink of the LiFePO is rubbed off there will be a short on the positive end of the battery (the battery casing is the negative pole). I think that happened here https://community.mnt.re/t/battery-failure/604 
The battery was discharged because the balancing resistor was always on while charging https://community.mnt.re/t/upper-left-battery-on-oled-discharging-faster/1071. I think the balancing process will take long time with such a difference in Voltage. I’ll try charging the cell with an external circuit. If the cell is dead I will ask you for the giveaway - Thank you 
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