Description

21700 cells from disassembled Tesla batteries. Each cell comes in new heat-shrink wrap with an insulating ring on the positive terminal, ready for assembly. 100% of cells are tested and sorted: this group has a capacity of 4.6–4.8 Ah and an internal resistance of >15 mOhm. Use cells from the same group in one battery pack so the cells work evenly and charge uniformly. The lower the internal resistance, the better a cell handles current and the less it heats up. For a pack built from identical cells, the difference between adjacent resistance groups is small; what matters is that all cells in the pack come from the same group. For convenience, we can laser-weld bimetallic aluminum–nickel contact pads onto the cells. Wires are easy to solder to such a pad, and nickel strip can be spot-welded to it. The service costs UAH 20 per cell.