A month or so ago one of our quartz clocks stopped and when I changed the battery, found it to be leaking. There was quite a bit of corrosion and it took quite a bit of effort to clean it up. A few weeks ago we were travelling and (even though they were still running) took our "good" watches to a master watchmaker known to us to put new batteries in them. He said it's a good idea to do that after about 4 years even if the watch is still running, and within a year if it stops. So I started looking at our other remotes, clocks, etc having batteries. I found a number of leaking batteries, some outside the best before dates, but many within. All in all I found 8 or 10 leaking batteries. If anything, the brand name batteries were the worst performers. So - it would be a good idea to check all your batteries. I'm also going to remove the batteries from unused controls until I want to use them.