Could I be right in thinking that using a battery charger to recharge
a run-down car battery tends to reduce the life of the battery? On
more than a couple of ocasions, car batteries I have owned have not
survived long after I have used mains plug-in chargers to recharge
them.

The reason the batteries needed charging was not due to any fault in
the battery; it was due to the cars having ben standing, undriven, for
a long time.

Thanks,

Hank