I have a battery powered shaver that takes 3x AA batteries. The charger I have will only charge batteries in pairs. So in the charger I’m going to have to put in an empty battery with a full battery (the spare one that wasn’t used in the shaver). Is this safe? Or am I better draining the full battery first somehow (maybe in a torch)?
An additional question: most chargers seem to charge AA’s in pairs. Is there any particular reason for this?
I’m in the UK with 240V mains if that makes any difference.