> Contrary to what many people believe, completely discharging a lead acid
> battery doesn't do much harm. Mostly, *the damage is done when
> recharging it. I think you are looking at something like 3 days to
> charge a fully discharged battery with 1 amp.

Hard recharges do damage batteries, and long slow charge works
reasonably well on dead ones.
However, heavy discharges do damage batteries. They may survive
several deep discharges with no apparent harm,
but each time a car battery is forced below 10 volts, plate damage
occurs in the form of sulfur dendrites(?)
Some are knocked off or dissolve during normal cycling, but not all,
and this takes up active area on the plates.
HTH
Ben