One of my fav lights just died.....sort of!!

I bought one of the single AA Energizer lithium lights about a year ago, and I love it. Use it around the house all the time. Yesterday I turn it on, and all of a sudden, it is about 50% as bright as it used to be. I tried several more batteries, cleaned all contacts, swapped the tail out with another one, and the problem remains. The light still ramps up and down, but again, is only about half as bright. I know there is a lifetime warranty on these lights, but I no longer have the receipt. Oddly enough, I still have the package it came in! The only thing that is kind of cool about this, is the low now is about where I would have made it if I designed the light. Does anybody have any ideas what may have happened? I am guessing the problem is in the head with the emitter or driver, but there is no apparent way to get to it.

Often companies like Energizer have very relaxed rules about receipts, etc. IIRC, there was a member here who sent pieces of a flashlight and no receipt and the company replaced it, no questions asked. I think they get a bigger lift from the free advertising than by recovering the few bucks the original light cost. If you're low on coin, it couldn't hurt.

My experience with Energizer is from a broken Clip on a 1 watt cree. I called CS and they promptly sent me a $15 coupon, approximately the replacement cost of an entire light.

Call them, I've very seldom had such good customer service.

Thanks to those who replied. I may just give them a call and see what they can do for me.