I have 8 empty cases
Thanks for doing the measurement.
I would rather go with the 21700 cells
Lift uses a 3” to thick battery. I believe that’s also the max you can fit within the board. 76mm. Maybe 80mm fits too?
In that case a custom 21700 battery would fit for sure.
So the vertical measurement for the internal is just under 70mm. So I wouldn’t use the 21700 vertically. However if you place them on their sides you can do a 14S12P pack with a config of 4x 14s3P in parallel which works nicely. It will actually get you a way larger battery than the old 18650 cells depending on which cells you want.
I actually have a working lift ebox and 2 batteries with working BMS as well as the 2 extra battery cases. If you want to chat further hit me a PM so we can discuss this outside of this thread.