Building a 24V Li-ion pack for a follower’s electric wheelchair; single 15Ah LiFePO4 cells, Jiashikai 32140 (label IFR32140-15Ah 3.2V 48Wh; capacity 15.60–15.75Ah, internal resistance <2.5mΩ, voltage 3.293–3.298V). LiFePO4 is 3.65V per cell, so 24V needs 8 in series; 30Ah needs 2 in parallel, 8S2P, 16 cells in total. Laid into the holder alternating + / −; fish paper on the positive ends for insulation; laid out and locked in with the top holder; with the holders on it is very rigid, there is a gap between each cell, good for insulation and safety. Welded with 0.2 thick nickel-plated steel strip; a capacitor spot welder with the current set to 30 welds 0.2 nickel-plated steel strip easily; each cell is welded 3 times, 6 weld spots, so current capacity is assured; after welding every spot is checked for loose welds. Fitting the BMS: a LiFePO4-specific 8S board (Shenzhen Bozhi BZ808-5080-030C30-B-F-8S, 8S 30A LiFePO4, common port, balancing, temperature control); the harness is tidied and soldered in order to the matching tabs; with the BMS on, the 16-cell pack is shaped very flat to suit the battery bay; finally a charge / discharge test. 191 comments: how much for Jiashikai 32140 in 72V45Ah (4); how to build 96V30A for a two-wheeler split into two locations (2); where to buy the welder, want one (1); how much for 12V20Ah (1); how much for 48-30 (1); 3.65 × 8 = 24V (1); OK for a trike (1); is the AWithZ welder any good; welder link please; don’t use this pack on a big delivery e-bike.