There was a post about how much to discharge a battery...

[St8kout]

I could not ask a question at the time because of the email registering snafu, but someone said he let his batteries go way past the 50% discharge point and simply limited the number of charge cycles to make the batteries last longer. I can't seem to find the post.

My question is, how does he manage the recharging? Does he turn off the charge controllers until the batteries reach a certain level, then turn them back on or what?
I assumed you match the battery capacity to the power requirements so that by the next day they get recharged before dropping below 50%. We very seldom get cloudy days in Vegas so recharging is usually every day.

[Mike90250]

The depth of discharge is managed by sizing the battery to the expected load, so that in normal conditions, only 20% of the battery power will be drawn off in 1 day.

[St8kout]

Hmm, but won't the charge controller still try to top them off unless I physically disconnect the panels?
I thought his idea was to limit the number of recharges.

[Mike90250]

You want to batteries to stay fully charged. When they are not fully charged, the electrolyte (in lead acid batteries) begins a long slow process called Sulfation, where the acid deposits sulfur crystals onto the battery plates. If recharged quickly (less than 24 hours) the sulfur is driven back into solution The longer the crystals sit, the harder it is to revert them back into solution. As tiny as the crystals are, they block a portion of active plate material. Eventually over months, appreciable areas of plate are blocked and battery capacity is reduced, all because of counting cycles and NOT recharging.
Battery management is a knife edge between Sulfation and Positive Plate corrosion. Eventually batteries die and need replacement.