How much does or can the battery affect the electrical system of a sled. I've got an electric start ski doo 800 2006 and am having issues with the electrical system now. I've got headlights, and my tach reads rpm's but won't light up or display the odometer. I've also got no reverse, no tail lights and I don't think my handwarmers are working either... what do you guys think... I was reading around and it sounded like it could be a bad battery. How would i test for that or what else would you suggest. I don't have a battery charger. It also runs really poorly.