Can anyone tell me what the Voltage rating is of the Mini SE High Voltage main traction battery? I know it is rated at 32.6 kWh's and I know the Mini also has a 12 Volt accessories battery but I was wondering what the main high voltage traction battery is rated at in Volts? I can't seem to find it in the manual or anywhere else.
Nobody really knows until there is a teardown of the modules. There are 7 modules in a 1-2-4 T shaped arrangement. 5 modules are double-celled and 2 modules for the tunnel are single cell. If you take the BMW 94Ah i3 (Samsung SDI 94Ah prismatic), it is 8 modules of NCM 333 with max 4.15V per cell. There are 12 prismatic cells per module all in series (nothing in parallel) so the voltages are added taking you to 398.4V (4.15 x 8 x 12). For the Cooper SE, to get the 4.15V you would have to have 8 CATL cells in a single pack module (x2) and 16 cells in a double pack module (x5) to get 96 CATL cells. In short, our best estimate is 398.4V for the high voltage battery! edit: 120Ah BMW i3 went to NCM 622 but has a better battery thermal system (R-134a refrigerant vs water/glycol in the MINI...R-134a is now banned in USA for vehicles for 2021+..coincidentally with the i3 being discontinued in the US) Going to NCM 712, 811 or 9-0.5-0.5 requires significant cooling (ie. pouch cell tab cooling) to prevent thermal runaway.
Noted auto photographer and fact dispenser, Paul Tan, provided these MINI Cooper SE battery specs on 2/3/20: 32.6 kWh CATL T-shaped battery (28.9 kWh usable @ 350.4 Volts).
