Saplina Julia/Shutterstock A flat battery is a situation pretty much all of us will have come across before. It’s perhaps most annoying when you hop into your car. You’re late for work or something, crank the key and… nothing. The same can happen with your riding lawn mower, too, and there’s never a good time for it. According to industry experts, lawn mower and battery suppliers, your riding lawn mower’s battery should be good for at least three to five years. Ther...