I bought an 18 Volt Ridgid combo kit at HD several years ago. It has worked great but the batteries appear to be at the end of their life. They are about 4 years old...I don't think that they are covered by the lifetime warranty. I just looked on EBAY and there are lots of batteries at a reasonable price but they could be years old. What got my attention were several peiople offering instructions on how to "re-condition" all types of batteries. Sounded too good to be true...does anyone know about this "Re-conditioning?"