I just bought a somewhat older laptop, though I hope you will all forgive me if it is slightly younger than the borderline for the interests of this group (I am not sure on which side of the line it lies.) It is a Toshiba 4010CDT, which uses a Li-Ion battery, the subject of this message. I am amazed at the number of contacts between the battery and the computer (about 10) and wish to know their function. On the Internet I find nothing. On account of the short life-time of such batteries I want to install NiMH. I accept that I would have to use a separate, external charger, even removing the reserve battery fro the charging process, as the price of being able to travel with a back-up battery which would not die after two years of having it around. The problem is all those connections; I have no idea what they do and only a couple of them are needed for transfer of power to the computer. At least part of the rest must be communicating data about the state of the battery, either for the sake of charging or for warning of the soon-to-come shut-down for lack of enough power to continue. I would have to lie to the computer in such a way it thinks it is monitoring a Li-Ion battery, but to do it I need to know what the lies must say. Does anybody have a clue what the functions of these connections are? Keeping my fingers crossed, Bob