Board map

  • green box
    • 18650 battery on the backside of the baord
    • 2x AA
    • 1x AAA
  • purple box
    • serial connector jumper for 2x AA (will to change to 3-way jumper later)
    • LED plug-in port (serial connected 1K resistor)
  • red boxes and red arrows = active battery selector
    • AG3 x1 x2 x3
    • AG13 x1 x2 x3
    • 18650 battery, 2x AA, 1x AAA
    • CR2032, CR1220
  • extra plugger, left -, right +
    • XH2.54 port
    • XH2.00 port

note

  • all the series battery should be same brand, same brand new batch
  • PRESS slighly hard in case the battery holder didn't hold the batteries well
  • all the jumper can be used to insert voltage monitor
  • insert only ONE battery group once

test

  • AG3 = LR41H, battery drop from 2.9V to 1.6V when run the led

demo

version

ref