Larry wrote:
. . . Schumaker SE-1-12S "1.5A Fully Automatic Onboard Battery Charger/Maintainer".

I'm wondering, would one of these things fully charge a discharged
*big* bank of lead acid batteries, like 500AH capacity? It'd take 20
days or so, but could it do it without harm? Would the gentle charge
rate stop sulphation during the 20 day charge? A half dead lead acid
battery sittin' around for 20 days would sulfate up with *no* charging
going on. And could 1.5 amps drive the batteries up to 14.2 volts?

Never tried such a thing - tiny charger, big batteries.