I know they used to make lifting handles for batteries that either lift by the terminals or by clamping on the side of the case. You could check at a auto supply store or tractor supply type store. I bet wal mart even has them. These are just temporary lifting devices, you remove them from the battery when done moving the battery.
Take your wingnuts off the terminals and put a flat washer on each one, then take a piece of nylon rope and make a slip knot in each end putting one end on each terminal, add a flat washer then you elec cables and tighten the wingnuts back down