I recently went out of town for 4 weeks and forgot to disconnect my battery before leaving. When I cam back the battery was (not surporisingly) dead. I was able to jump it and start the bike but as soon as I disconnect the jumper cables, the bike dies. I know I need a new battery anyways but it is my understanding that the battery is only used to start the bike and then the stators and the rest of the electrical system power the spark plugs and electronics once the engine is running. I'm worried that I may have a bigger issue here than just a battery. The bike is a 2005 with 1800 miles. Any ideas?