Huge wrote:

And I'm going to buy a second one for the (ride-on) lawnmower, whose
battery is dead as a door-nail, as we discovered yesterday.

Ride-on mowers and mini-tractors are really battery killers in my
experience, not because they work the battery hard or anything but
simply because they get left unused for long periods. As many others
have pointed out here it's leaving lead acid batteries uncharged (and
thus self-discharge) is what kills them.

I have both a ride-on mower and a mini-tractor and after losing a
couple of batteries this way I now have a Gunson's "automatic" charger
for each which is left connected most of the time, but especially over
the winter.

(That reminds me, see separate thread about connectors)

--
Chris Green