My pocket camera has begun kvetching about a low battery rather more often than before, which suggests the batteries I’ve been using since 2014 have gone beyond their best-used-by date.
This came as no surprise:

I re-ran a couple of the batteries to make sure they hadn’t faded away from disuse, which didn’t materially change the results. The lightly used Canon OEM battery continues to lead the, ah, pack.
The camera’s lens capsule accumulated a fair bit of dust from many years in my pocket, which lowers its overall contrast and wrecks the high f/ images produced with the microscope adapter.