I posted a thread here from back in like 2013 or so, where I pointed out that the 18v batteries for my Rigid 18v hammer drill/circular saw set that I had purchased way back in late 2003 were still going strong then. But finally, just 1 year later, 1 of its 2 NiCad battery packs had given out, and the charger suddenly began refusing to charge it, and gave me flashes to let me know there was a problem with it. I was right in the middle of replacing 2 banisters, armrails, posts and safety rails on a large deck. I had to finish with 1 battery, but the set had come with a lifetime warranty back in 2003, including batteries. So I dropped off the 2 batteries after talking to a Rigid and Home Depot reps. Less than 2 weeks later, I received 2 new batteries and a new charger for free! I use it less now than before, but I was impressed with how long those old NiCad batteries lasted! I assume the new battery packs are NiCad, and weren't replaced with NiMh internally....