One was an alarm clock that suddenly stopped working. There, the battery had a 'best before' date of March 2019.
The other was a small aluminium LED flashlight where the battery had swollen to the extent that I had to drill a hole in the battery base to extract it. The battery there had a 'best before' date of March 2015 so was out of date, although the flashlight performed perfectly.
The damage is not great, in fact I have more or less cleared it up, it is more of a nuisance. It is also the loss of confidence in the quality of the batteries and the amount of effort it is to check all devices (flashlights, clocks, cameras, fire alarms, TV remote controls, radios, computer mice etc. etc.) to see the battery is beginning to leak.
I have always bought a well known battery brand and have always bought them from Migros/Coop in large packets (say 12 or 16) so I should not have a problem with counterfeits.
I have had done a google search and discovered (1) one manufacturer's batteries appear to dominate the 'bad battery scene' Link (2) Energizer, another manufacturer of batteries well known in Switzerland, appears to give a no leak guarantee on it's US site, but I can't find an equivalent on it's European site.
Has anyone had a practical experience of claiming against battery guarantees?
Disclaimer: I have no commercial interest in any battery manufacturer (as far as I know).