convert excess heat to electricity to charge the battery or the 48v battery?

[richguy]

https://www.science.org/content/article/cheap-material-converts-heat-electricity

using tin selenide, etc. you can use excess heat to make electricity. Imagine the heat produced by the sun on the outside of the vehicle.
How about the excess heat produced by the motors?
Granted that there has to be a heat gradient hot to cold to produce power.

 

[LoudMusic]

There are many ways to add micro energy producers. The cost and complexity to add them to a vehicle is prohibitive when alternatively more battery capacity could be added for less cost and greater reward.

If cost was irrelevant then sure, add all those things and get another 10 to 15 miles of range per day. But keeping costs down is important for sales.