“Working on a pack that size is like working on a live bomb.”
A stock 500 Wh pack got him 45 km on a fast e-bike. He spot-welded 190 cells into a custom box and now gets about 180 km at full power. The hardest part was not the welding. It was Bosch’s battery management system, which is DRM built to stop exactly this. Bosch would rather sell you three spare batteries.