That is the PRAM battery. If ever your computer refuses to boot disconnect it and it will probably work. The PRAM battery keeps time and performs several other functions but the computer will run without it. You just have to reenter the information every time you start up. Hope this answers your question. Ralph
That is the PRAM battery. If ever your computer refuses to boot disconnect it and it will probably work. The PRAM battery keeps time and performs several other functions but the computer will run without it. You just have to reenter the information every time you start up. Hope this answers your question. Ralph