Custom 6cell battery for T420 using LG MJ1 18650 cells : r/thinkpad
This is my T420 which I've had since I was 8. Obviously, an 8 year old is not gonna take very good care of a laptop, and while this one is in
IBM/Lenovo ThinkPad Z61t. It's pretty old, but still good. : r/thinkpad
T420S battery upgraded with Tesla model 3 21700 cells, also upgraded the wiring that connects the cells to the BMS from 1.5mm to 3mm conductor size (voltage drop went from 0.7V under