The Natural Philosopher wrote:

Still die on deep discharge, they just go a BIT deeper that's all,
and its not that much.

Friend of mine had a canal boat,..tried em all. All failed.


I'm speaking from considerable personal experience, not merely an
anecdote from a friend.

Bill

so you have run several deep discharge batteries totally flat, and they
have all survived?

Yes exactly. There are two reasons.

1. I use seven such batteries in my motorhome and occasionally some of
them are fully discharged. I don't like this to happen but sometimes it
does, accidentally.

2. A friend of mine has a mobile display unit for his fountain control
valves. I rigged up a battery/charger/inverter arrangement for him, to
power the pumps. Several times the battery has become very deeply
discharged. Recently he did a demo somewhere in the Middle East and
didn't get a chance to recharge the battery until he got home, but the
battery survived.

Bill