This is a dual charger that accepts up to 30V through the XT60 so you can charge in the field.

Required parts
1-2 paper clips
2x green 3mm LED's
2x red 3mm LED's
XT60 male connector
1x Sliding switch
2x M2 screws for the switch
2x 03962A charging boards
1x MP1584 voltage regulator
4x 10mm M3 screws
2x 1.8k 0805 resistors (optional)
Some wire, heat shrink, solder and hotglue

I know you can buy the commercial equivalent pretty cheap but I had all the bits so thought why not!

It should go without saying Lipo's are dangerous I take no responsibility if you blow yourself up doing this.

Change R3 on the 03962A for 1.8k resistor, I found during testing that charging the 18650 at 1A makes the 03962A get too hot for my liking 80+ degrees. Changing R3 for 1.8k reduces the charge current to about 700mA. It still gets to just about 60 degrees but that’s better than default.

I wire the LED's to the LED's on the 03962A the two LED pads next to each other are VCC. You should remove the red one otherwise it illuminates internally and makes the external one dimmer. (the blue one has a higher forward voltage than green so can be left attached)

I have hot glued a cut up old plastic bag between the two battery compartments, this means to remove the battery I pull the plastic.

Make sure you get the right bend on your paper clips else it will mark the batteris terminals