18650 battery compatible with Milwaukee 2.4V screwdriver

prusaprinters

CAUTION: Running a motor from an unprotected lithium cell can lead to over-discharge, over-current, and other bad situations. Build and use at your own risk.A very simple and cheap rechargeable lithium battery compatible with Milwaukee 2.4V screwdriver.Requires:18650 battery (I used ones salvaged from an old laptop battery)M2 by 8mm screwsOne of those common TP4056 charger boards in USB micro or type-CPair of metal strips around 20mm by 6.5mmInstructions:Keeping wires short as possible to make assembly easier, solder or spot weld wires to battery terminals. Insert metal strips into pocket near positive and negative marker on battery body and fold strips back into J shape.Connect positive terminal to B+ and metal strip on positive terminal. Connect negative terminal to B- and metal strip on negative terminal. Do not use OUT terminals on TP4056, the motor current will blow up the protection IC.Screw in terminal retainer to hold terminals in place.Insert locking tabs into battery body and pin in place with M2 screws. I found the PLA ones crack eventually so I made a TPU version. Fit can be tight so try printing with reduced flow.Screw spacer into charging plate and then screw charging plate to battery body with M2 screws.Notes:I made a USB mini and USB type-C variant. The mini variant has a TPU dust cover over the charging port but I removed that for the type-C version.