What does completely draining a battery do to battery life?

[Jonathan Wilson]

I'm looking at buying some AGMs from a fellow who has a several that he has
never used.

They are "new" still in the original packaging, however they are two years
old.

He said that he charged them and they have held a charge ever since
he charged them. I assume he meant he recently recharged they and they are
ok.

However I assume that in two years time they must have been quite dead
(fully drained) for a while.

So I have a question: If AGM batteries drain all the way down once and are
not charged for a long period, does it hurt the life span overall?

JW

 

[Eeyore]

So I have a question: If AGM batteries drain all the way down once and are
not charged for a long period, does it hurt the life span overall?

Yes, it totally screws it beyond all belief.

Look up 'sulphation' or maybe that's sulfation in American.

Some claim the worst effects can be reversed with care.

Graham

 

[Jonathan Wilson]

On Fri, 21 Mar 2008 04:46:04 +0000, Eeyore
4) IMHO, and that of a few others even more familiar with the
problem, only one manufacturer on the planet *really* understands AGM
recombination cells, unfortunately that independent manufacturer is
now in the hands of another corporation,

What company is that?

JW