Battery Packs

One Side

The Other Side

Finished pack wrapped in electrical tape but no connectors.

Battery pack in the board. Fits well.

One of the two battery packs made up of 30 18650 Samsung Lithium Ion Cells. The same type of batteries that Tesla uses in their cars but I think they use Panasonic batteries. Each row of 5 is wired in parallel with each other with braided wire and those 6 are wired in series to make a nominal voltage of 22.2V (3.7Vx6=22.2V). I used hot glue to glue them together and glue in the wires between the gaps of the batteries. There has to be a wire between each parallel wired row for the purposes of charge balancing. The main end wires are 10 gauge to handle the high amperage. According to the spec sheet each battery should put out 2C with a 2.6 amp hour capacity equals a 5.2 amp max discharge current per cell. That times 30 cells equals (30x5.2A) 156 amps max discharge per pack. Which is more than enough for the two 120A motor controllers and the two 90A BLDC motors. Link to the Samsung 18650 cell spec sheet.