Hi, I have an four year old battery that has started cutting out whilst going up hills. It only works if I turn the key to off then on again. Its been fully charged up before I set out so there should be plenty of juice in it. Just in case this was an indication that the battery was nearing the end of its life, I went ahead and bought a new one and this has been charging up for at least three hours and the small LED has still not turned green (does it normally take this long to charge up a new battery? I thought they came fully charged).