[roady89]

Yes..You can do it but the run time wont be much more than what your getting now. You could get some deep cycle marine batts to get a little more but not much. There is a date code stamped on the terminals....can you post the 2 digit codes and we can tell you how old the batteries are.

Possibly the batteries are toast if they have been drained for a long period....try charging them again overnight and see if the run time increases....be sure they have water to the proper level and be sure all your cables are clean and tight.