Store the energy for the endurance event.
105 series by 6 parallel Sony VTC5A 18650 cells in ENEPAQ 1s6p prepackaged submodules. 446 V maximum, 270 A maximum, 15.6 Ah, 6.96 kWh total, roughly 5.64 kWh assumed usable.
Pack parameters came from the OptimumLap simulation run to convergence on mass: run at a given final drive, record energy spent per lap, feed the new battery mass back in, repeat until mass asymptotes. Initial targets were 420 V nominal, 130 A nominal, 210 A peak for 120 s, 6.552 kWh preferred capacity, and a hard 80 kW power cap from rule EV.4.1.1.
EV.8.4.1 requires cell voltage measurement of every cell. EV.6.2.3 requires nonflammable insulation between segments. EV.7.6.1 requires overcurrent protection on all electrical systems. EV.8.5.3 to 8.5.7 govern where temperature is measured, how many cells are monitored and how the sensors are isolated. EV.4.1.1 caps power at 80 kW.
Sony VTC5A 18650 LiNiMnCoO2 cells: 15.6 Ah, 4.2 V maximum, 3.6 V nominal, 2.5 V minimum, 36 A maximum charging current, 60 C maximum discharge temperature, 45 C maximum charging temperature. ENEPAQ submodules add two fuses per parallel group, built-in temperature sensors, UL94-V0 fire-retardant plastic, copper terminals and copper busbars with M5 bolts.
The original layout was extremely difficult to package in the car. Internal resistance of the pack has not been measured and there is no thermal model of the batteries under load yet.
CR25 one-pager costing: Sony VTC5A 1s6p modules at $85.03 per module, $11,768 for 120 modules, plus maintenance plugs at about $460. No manufacturing needed as the modules arrive assembled; manufacturing is required only for the accumulator structure and the high voltage connections, busbars and maintenance plugs. Quantity per car, as costed: 1
Nothing in CrimsonStorage covers these yet.