Is there such a thing as a battery backup for a regular sump pump? In other words, I want to plug my existing A/C pump into a battery backup (or UPS) and then plug the battery back up into the A/C line.

I know there are battery backup sump pumps that can be used along side a regular pump that will kick in during a power failure, but I don't want to have install anything in the pit, or run new lines.