What they said..

Betteries are cheep insurance..

If the motors won't loosen up do a search on the crock pot method using antifreeze.

I was out for 15 years and most of my engines were a complete lock up.. The crock pot got em back to new.

Oh yeah.. some of the cheep ARF hardware can become brittle over time..

I got my Avistar from a friend who kept it in storage for 5-6 years.. I had to replace all the contol horns and clevises.