I took the bike out the other day around town for about an hour. Did 5 stops with no problem, then backing it up 40' up the hilly (10 % incline) driveway into the garage. Then turned it off to open garage door & it wudn't start again. All I can figure is reverse is electric & maybe wore the battery down, altho it says 12.15 V on the multimeter. In all fairness, the battery connections were a little loose, but obviously good enuf to drive around all summer. How can I prevent that from happening again? Just take it for a good run to charge up the battery?