Lylou2 wrote:Ok if I use f.eg. extra battery pack in baggage aprox 10kw/h, how does the charging/discharging gonna work? Or it deals in 2 batteries or its cannot be too 'heavy' for smaller battery?
The simplest and most efficient way of adding a range extender (which mux and others have attempted) is to add a second battery pack of 96 cells in series (~370V nominal, 412V max, 320V min) via tap off the main HV cable, through a second set of contactors controlled by the main contactor controls. Charging and discharging is done at the same time as the main battery pack, by necessity, since it is "directly" connected when the contactors are enabled during charging/discharging. For small extender packs (e.g. ~1-2kWH) then the cells should be able to handle effectively the full charge/discharge C rate that the main pack handles, as its contribution is very small. In the case of the 24kWH Leaf, ~5C discharge, ~2C quick charge (max, tapers quickly), and ~1.6C max regen charge. For larger battery packs, the overall charge/discharge rate will drop as the total capacity of the pack increases (since the charge/discharge limits stay the same). For 10kWH + 24kWH in your example, discharge will drop to 3.5C, quick charge to 1.4C. The other factor to consider is the extender HV cabling will need to handle nearly the same current as the main pack if using a different chemistry like mux found with the NCA cells; at the tail end of the discharge curve, the extender pack was taking nearly all the load (almost no usable capacity left in the main pack). This works out to ~2 or 3ga cabling.