On Wed, 16 Dec 2020 12:53:23 +0000 (GMT), Dave Plowman (News) wrote:

Some if they are off a building site or a repairman who is
attending
several calls may be taking the opportunity to top up the
batteries of
Cordless tools ,most of the well known tool makes like Makita make

chargers that work off the vehicle accessory socket.

Sorry, I simply don't believe every van running its engine when parked
up like this has a good reason to do so.

No one said it was a good reason. B-) If I was doing that I'd have
an aux battery for the chargers to avoid them accidentally being left
on and flatening the vehicle battery.

Suspect a combination of heat(*)/coolth and/or listening to radio
and/or battery charging are the reasons.

(*) Though diesels barely put out any heat when idling.

--
Cheers
Dave.