I grabbed my Fenix EO1 to check out the basement dark areas for water leakage. The head would not turn at all. I instantly knew what had happened. I put on my safety glasses & with much effort managed to unscrew the head. A loud pop ensued like opening a soda can. Sure enough the negative side of the Energiser had a glob of clear fluid on it. I used vinegar followd by alcohol to clean it throughly & works fine now. It was not subjected to heat & I use it everday yet, it still leaked on me. Thanks to all you guys for posting proper cleaning methods on the Alkalines. You saved my day!