I recently went to change the battery in a flashlight that I use daily. To my surprise, the upper battery had exploded, leaking goo all over the interior of the flashlight, cementing itself in place in the process.

"my battery blowed up"

In order to return this fine flashlight to service, I had to solve the stuck battery. What wound up doing the trick was distilled vinegar. I shot some vinegar up the tube, which dissolved the hardened goo. After a few minutes I was able to retrieve the battery by lightly pounding the tube on a counter top. I then rinsed out the vinegar.

I more calculated that this light was more or less toast, so the risk of getting the innards wet didn’t really bother me. I tried to minimize the time the insides were wet, and I shook excess moisture out (vigorously). Then I let it dry before I put the batteries back in.

The first attempt failed–there was some chunks of dried goo that blocked the circuit. Once I got those out of the flashight tube, my light was working again. The battery leakage damaged the anodizing on the inside of the tube, but you won’t see that.