Reverse (electric?) and Towing

[Toyota Curt]

I backed a trailer up my driveway today and my driveway is a pretty steep hill, I noticed that reverse seems to only run off of the batteries. By the time I finished parking the trailer my batteries were pretty well drained.

Does anyone know if there is a mechanical reverse that is driven off the engine in case the batteries run down?

[Chevalde3]

There is no way the engine can help move mechanically the car backwards but it can recharge the battery. For 4wd-i, be aware that MGR (rear motor) is not water cooled and will shut down if overheated. So if you have to go a long way backwards with a load, pause frequently when battery is low to cool down MGR and recharge the batteries.