James- How old are the batteries? You can try and fully discharge them then fully recharge them. If that does not work the only thing you can do is purchase new ones. Sears sell replacement batteries for most models. from time to time they run them on sale really cheap. Last fall I purchased 19.2 volt C-3 batteries for $25.00. I have 12 tools which run off these batteries so I purchased 4 packs as spares to go along with the 6 packs I use. From what I've read these batteries will not go bad if not used. I been told you can only charge discharge a battery for some many cycles. I also been told not to leave them in the charger after they have been fully charged. Hope this helps ya.