21700 battery case 2s, 4s, 6s with springs fast replacement

thingiverse

Case for 21700 batteries to recharge FPV batteries in the field. Cells are held by springs so they could be easily removed and charged with a Li-ion charger. One could add wires for each cell and use output balance connector to charge whole pack together, also it is useful to check voltage using a portable battery tester. Original SLDASM file attached. Feedback: I've tested only 6s in field. It looks like this springs are too small for 21700 batteries, but it works anyway. ###### List of additional items you will need to build case: 1) AA or AAA battery shrapnel springs 1 cm * 1 cm. I use [these](https://aliexpress.ru/item/32881285245.html), they fits nice when tendrils are flatten with pliers and depending on how strong you flatten them you can regulate how tight they will be inserted inside case. Unfortunately positive contact bulges out too little to use with flat cells as is, so it needs to be increased, so add a solder ball on a tip. 2) Main wires with 2.5mm outer diameter. 18AWG is enough for up to 22A. More flexible silicone wires are preferable. 3) XT60 female connector. 4) 25mm wide strips cut from the lid of a tin can for jumpers 5) (optional) Balance wires with 1.7mm outer diameter (usually 22AWG). More flexible silicone wires are preferable. 6) (optional) XH2.54 balance connector with pins. 3pin for 2s, 5pin for 4s or 7pin for 6s. 7) Stuff for soldering: iron, solder, heat shrink, etc.