Hi, I was wondering if anyone could chime in about this. My friend has a 1800C and we just put in a new battery from Batteries Plus. The battery only fits one way and once we hooked it up, we realized that the new battery is opposite polarity than it is supposed to be. After trying to start it, I noticed the backwards polarity. Now the bike starts and runs for a couple of seconds and sputters out. We didn't even think the battery could be backwards as it only goes in the one way to hook up. Any help would be great. Thanks.