The Adafruit Micro USB Li-Ion and Li-Poly Charger is a must have for any toolbox, with a constant 100mA charge current, you just plug it into a USB port, attach a battery and wait for the green LED. It is specifically designed for charging the 3.7/4.2V lithium-ion or lithium-polymer batteries rather than the older 3.6/4.1V batteries. It uses a 3-stage process, starting with a preconditioning charge, then a constant current fast charge and a final constant voltage trickle charge to keep the battery topped up. Should you need a higher charge current there's a solder jumper on the back to boost it to 500mA for 500mAh or larger batteries.

Supplied as a fully assembled and tested charger plus a JST connector with flying leads.

• PCB style USB connector
• 100 or 500mA constant charging current
• Red charging LED, green battery ready LED
• 3-step charge routine for lithium batteries
• Adafruit part no.: 1304

*Customers looking to resell on eBay or Amazon should contact Adafruit directly.