I had the same happen on a big 5 D cell maglite. The batteries also swell when they fail. I literally set it on an oak board and hit a 1" steel rod on the battery with a sledge and it would not come out, collapsing the end of the light. The problem with LED lights is that the battery can be mostly dead, swelling, and leaking, and the flashlight still works. We check the batteries monthly now which is a PITA but it seems the only way to stop that. The suits and bean counters have pretty much destroyed those guaranteed to work for 10 years statements. If they do warranty something they want so much paperwork that it is impossible to qualify. Usually it falls into a black hole, and a month later a letter comes back with a denial because you didn't send them what they asked for (which you did), and a phone number to appeal, which the call goes straight to a desk that no human sits at.