On Wed, 22 Jul 2020 11:25:26 +0100, "Dave Plowman (News)"
wrote:

In article ,
Theo wrote:
I think I might need a new car battery charger. However I'm failing to find
anything suitable and wonder if the team can recommend any models.

Requirement #1 is to be able to charge flat batteries.
My boot lid sometimes doesn't latch properly and leaves a dim little light
on - which if you don't drive for a week or two empties the battery. My
current 1980s dumb-charger can't handle delivering current into a low
voltage battery for more than a few seconds before the thermal trip goes[1].
I've seen smart chargers say 'we handle flat batteries 7.5V' which is no
use when the voltage drops below that.[2]

Most modern chargers won't work with a totally flat battery. They use
battery volts to pull in the reverse connection protection relay. So you
may need to use a jump battery to get it started. Other than that, most
will limit the current demanded to what they can deliver.

I cannot imagine any of this is good for the battery. It seems to me
a destructive way of solving a minor issue.