I've had a couple (at least) of bad battery experiences recently. In the past I didn't worry too much, as although the batteries went bad they didn't actually cause too much damage. Now I've had some big failures which have effectively trashed kit, and have been significantly costly to remedy. Problems seem worse for some chespo batteries from a welll known electronics store, but even some "better" makes can cause problems.
If you've not checked batteries in remotes or wireless keyboards for some time, now might be a good time. Also put reminders to check every few months. I think also one of my cheap battery powered MD recorders may be stuffed, though it might still work via a PSU.