Personally I disconnected the headlight fuse when doing mine AND I kept the charger on the bike throughout. It's such an easy way to avoid potential problems, when it's already known that problems may appear if you have an almost charged battery. Had no difficulties at all putting the Power-tripp map in (after I copied the stock map off the bike and saved it as a .hex map, just to be on the safe side; coming from a computer nerd background I'm keenly aware of the need of backups...)