I normally use a LiFe 3S for the radio and my last one lasted about 10 years before puffing so bad that I couldn’t use it any more. I needed a quick replacement and wanted to use 18650 cells but they won’t fit in the stock battery compartment. Enter the 3D printer once again to save the day.

This battery cover has a relief so that two 18650 cells will fit in the compartment. You can add padding or whatever if they move around too much. I found simply taping up the cells like I normally would is enough to keep them solidly in place.

I printed the cover on its side, long side up, with a little painted on support in needed places. I may re-print this in black but this test print in draft mode turned out nice enough that I’ll probably just keep using it.