I generally replace the electrolyte in the battery when it fails a carbon pyle load test, then recharge it. I just read an article on pulse technology chargers that are claiming to rehabillitate batteries. One is from http://www.pulsetech.net/
. They were written up by Capt. Bill Pike of PMY. The article is in the April 2011 issue. There are other companies researching this technology since so many automakers are going to Hybrids.