I thought that this is going to the best place to ask seeing as I know a lot of you like to tinker away with things. I've brought a set of Cateye RC230's from my brother as I needed something a bit better than the cheap LED light that I was using for my commute home late at night. The only thing is I've read a couple of reviews and apparently he battery life isn't great and also the charger and battery are really fussy i.e. you have to run the battery down to a certain level and then charge between 8-10 hours as the charger isn't a smart charger. Anyway if I've not sent everyone to sleep already, I've heard of people changing the battery to something else, any idea on how I go about doing that?