Bosch ProCore battery has clever design, but it still fails. In this video I investigate the problem and fix it on the budget. If you want do something similar - here some used parts down below.

Use parts:
Diamond grinding bits: https://rb.gy/3d11u0
Cutting discs: https://rb.gy/a9l4qm
JST-HX 5s connectors: https://rb.gy/tdloow
Nickel tabs: https://rb.gy/c2sx49
ToolkitRC M7AC charger: https://rb.gy/7i2eww
Spot welder: https://malectrics.eu
Cells bought at: https://www.nkon.nl/