Handbags   (The sad, the bad and the ugly. Non-productive stuff here.)

Just checking batteries with my multi-meter when doorbell ceased to work.

Got a shock (surprise, not electrical) to get a NEGATIVE reading.

Thought at first must be a problem with meter, but worked fine when testing the new batteries.

Online search soon revealed that such polarity reversal does occur, but is a rare phenomena. Never come across this before in more than seventy years!

Anyone else ever experienced this?

Also, the putative cause, that a battery in series with a stronger cell is driven by the latter into polarity reversal. Well, fine. But this occasion BOTH of the 'in-series' cells had reversed!

So, a rare event within a rare event! How about that!

Wish my Premium Bonds would catch on to this behaviour.