“I bought a couple of lithium ion 18650 batteries to power electrical projects. However, I needed something to conveniently charge and use the batteries safely. So, I used one of the inexpensive, widely available charger modules, threw in a few switches and a step-up module. With this set up, I never have to pull the battery out of the holder. I can conveniently charge with a USB cable, and the charger will stop before the battery is damaged from over-charging. I can connect it with either male or female header pins. Then because the current flows through the module, the module will shut off before the battery is drained and damaged from under-voltage. Plus, I can select either the raw battery voltage (usually 3.7volts but it goes from 4.2v down to around 3.0V), or the stable 5 volts from a small step-up module.
One important note, there is a rare chance of a Lithium-ion battery catching fire. It is rare however it is possible. So, I acquired a Lipo-bag and charge/store my batteries in there. I recommend one of those and I put the link of the one I got at the bottom of the components section. Stay safe!
Here are the components and tools you will use.
- 18650 battery and battery holder
- 5 Volt step up regulator
- 3.7V Lithium Charger
- SPDT Slide Switch (x2)
- 4cm x 6cm Perf Board
- Male header pins (two pins x2) a pair of black and a pair of red
- Female header pins (two pin x2) a pair of black and a pair of red
- Hook up wire
- M2 screws (5mm long) and nuts (x2 each)
- 2mm drill bit
- Soldering iron and Solder
- Flush cutters
- Needle nose pliers
- Indelible marker pens (one red and one black)
- Lipo Bag for storage and charging”