yes, battery polarity can be reversed, but you will not revive it - any battery dead enough to accept a reverse polarity is scrap, I'd suggest sending it off to the recycler, exploding batteries are no fun .... and if that battery was part of a battery bank in your trailer, check the others

Bill

Moved over to the Passing Lane

"When we tug a single thing in nature we find it attached to the rest of the world" John Muir
"When we tug a single thing on an old truck, we find it falls off" me
Some TF series details & TF heater pics & Rust-a-holics Unanimous parking lot