Make 5 of these 3V Coin Cell Holders with Switch for use with 3V LEDs with this kit.
Kit includes 5 x CR 2032 Vertical battery holders, 5 x CR2032 Coin cell batteries, 5 x 1.5amp in line switches, 2 meters of Red wire, 2 meters of Black, 5 x heat shrink).
The outside pin on the battery holder is positive where you connect to red wire.
The black wire connects to the pin in the centre.
The inline switch fits to either wire.