Yeah, you bring up another angle to look at it from: even if the alerts didn't go off when the batteries are being used/stored properly, it would make it easy to create a lot of noise/false positives as part of an actual attack (were those batteries to be readily available).

They were for a long time, betavoltaics were used in pacemakers. They started using more conventional batteries because the betavoltaics far outlasted the actual pacemakers.

That's interesting. I imagine parts for an internal medical device would be able to be more tightly controlled than batteries for general usage, but maybe I'm wrong.