Today I have by accident thrown a AAA battery into a bucket of water. I fished it out of the water immediately (within 20 seconds or so) and nothing notable had happened and the battery is still full according to a battery test device.
Cats Scratching Ears with Parasites. If this is not the issue, then it may be related to parasites alone. Check your cat's ears for signs of ticks, fleas, and mites. These parasites can cause obsessive scratching, as the cat makes a desperate effort to relieve pain and discomfort. If your cat is not allergic, try using natural tick or flea repellents (or mite repellent) if that seems to be the issue.
One possibility is contact dermatitis -- an allergic reaction from something your cat has rubbed against. If the hair loss is limited to the lower legs, for example, it could be a reaction to a new rug. You may have to do some detective work to figure out the cause, but once you remove it, the hair should grow back. Your vet may prescribe a hydrocortisone spray to stop the cat from scratching. Alopecia can also signal a more serious problem, such as a hormone imbalance. Cats with either hypo- or hyperthyroidism (an under- or over-active thyroid) may experience patchy hair loss, and an excess of the hormone cortisol can cause thinning hair in a symmetrical pattern on your cat's trunk. These conditions must be diagnosed with a blood test.