Nickel is a small 5V power supply and charge controller designed to provide regulated 5V output from 4-8 AA NiMH batteries.

Coming soon.


  • ATtiny402 MCU
    • Ambient temperature sensor
    • Battery voltage monitoring
    • Enable/disable for battery charging and battery output
    • Serial debug output
    • USB power capability detection
  • Constant current charging
  • Boost-buck circuitry provides 5V whether batteries are above/below 5V
  • 1 USB-C port for power input
  • 2 XH 2.5mm 5V power outputs
  • 1 XH 2.5mm battery connector
  • 1 status LED
  • 45mm x 20mm board dimensions (V0)


  • Example firmware, schematics and documentation will be made available on GitHub