well, on vehicles, a 12 volt charging system is regulated to 14.2 volts (+- .3 volts). but my computer, using an 11.8 volt battery, has a charger / a.c.c adapter, that put out a whopping 19.5 volts. obviously, i do not know all the ins and outs of how this works with a computer. if the charging system for the battery is separate from the a.c. running of the computer, or if they are indeed integrated like in a vehicle. 19.5 volts seems like a lot of voltage increase, for all of the electrical components to handle, from the 11.8 volts they are designed to run on. battery life is not part of my question. that should, unless i am missing something, simply depend on how much capacity the battery has, and the amount of draw on the battery. while i am not at all familiar with exactly how a lithium ion battery works, i do not think they are something magical, that could do something crazy like make its own voltage as it sits, or is being used. most batteries will recover slightly after a substantial draw, if allowed to sit for a period of time. that is simply a chemical process. my question is just about why so much voltage difference between the a.c. adapter, and direct battery voltage.