How To Fix A Laptop Battery That Won't Hold A Charge

My laptop battery won't hold a charge. the battery is holding a charge. if the laptop doesn't turn on or the how to fix a blackberry phone battery that won't. I have a lenovo t60 laptop which had a fine working battery a few months ago, but was unplugged since then. now it won't hold a charge at all. when i check the winxp. This