Just noticed a open sign when I was driving by. 

https://en.m.wikipedia.org/wiki/Hybrid_vehicle_drivetrain    

What veehickle ever used that arrangement?     .

Look at the pictures of the trucks again. They all appear to be heavy haul or off road trucks where the tare weight is not normally a primary concern.

You can use it as long as you aren't powering wheels directly with it. Transports use it for refrigeration and to run APU. Why can't I use it to re charge battery then?