From the time I bought my bike in June 2009 I have had a problem first with the stock wet cell going flat and losing a couple of ounces out of each cell in as short a time as three days. The first week I had the bike it stalled here in town while I was running errands and would not restart until I pushed into a gas station and they were nice enough to put it on their charger for twenty minutes. I had been running the PIAA 1100x lights that the dealer installed intermittently during the day anytime there was a lot of traffic around. At the bikes 1000 mile service the dealer said they could not find a problem with the battery or charging system. I changed the battery to a sealed AGM type that worked fine for the rest of the year including several 400 to 600 mile trips. Over the winter the battery was kept in the bike on a BMW charger. This year I started having problems again with the battery again after a month of riding. I would usually keep the bike on the tender if I knew I would be too busy to be riding it for a while. If I was running the bike daily I would not put it on the charger thinking that just running the bike would keep the battery well charged. About 6 weeks ago the bike would stall for no apparent reason and would restart but would not run unless I kept the throttle open by holding it or setting the throttle lock to keep the revs up. Other club members said they thought it might be water in the gas so I pumped the tank out and filled it with gas from the station I usually go to, which seemed to work for a week. It was getting late for the 6000 mile service with 6700 miles on the bike so I called a different dealer much closer to where I live who when I asked him what might be the problem with the battery, he asked if I had had accessory lights installed when I bought the bike and I said yes. He claimed that some technicians wire the lights incorrectly. I brought the bike in and they said that the original installation was done incorrectly . The bike again worked fine for about a week and then stalled and when I got it home and put it on the tender it took much much longer to recharge to 80%. When I took it out again afterwards it stalled a block from my house. I'm figuring the battery is shot (I hope) so I replaced it with a slightly larger sealed AGM battery that required modifying the battery tray. The bike is still disassembled in my yard in my new summer time garage.