I have written the following to DeWalt. Let's see what the response will be.
I have a Flexvolt battery that failed. After charging it only shows 1 bar. I went to turn it in for warranty and the technician asked where I store the battery when not in use. I indicated that I stored it in my home workshop. After testing the battery he indicated that it had failed because I did not charge it on a monthly basis. He said, "If you don't eat for a week, what happens?" I responded that I get weak and ill. He said the same applies to the battery and that they fail if not charged at least monthly. I think that this is a real problem for DeWalt if this is true. There is no warning or instructions that this is necessary. I also saw two others at the warranty center returning batteries for the same reason. This seems to be an issue. How will deWalt handle this? What if I have other batteries fail? How long will you honor the warrantees on these batteries?