They probably have different ideal operating temps.metricus wrote:The Leaf already has a TMS for the stator and the onboard charger. Beats me why they did not add the battery pack to the circuit. But that's another topic.
And, AFAIK, the liquid cooling system for the Leaf motor and OBC isn't connected at all with the AC system and its refrigerant. So, it won't be able to get those bits cooler than outside air temp, which is probably ok.
FWIW, as I posted in the Bolt thread (with video), they have 3 separate "coolant" loops: the loop for the OBC, motor, DC to DC converter and maybe one more thing also isn't cooled by the AC compressor and is just sent to a radiator. The coolant loop for the battery does have its heat removed by the AC compressor system and apparently also has a 2 kW coolant heater. The 3rd loop is for the crap "water" heater and that's not connected to anything else.
And, there can be considerable extra complexity to cool each of the modules properly.
Maybe I'll get to watching the entire 1.5 hour video for the Bolt battery at https://www.youtube.com/watch?v=ssU2mjiNi_Q someday.