Re: Dynasty Group 31 AGM (was Battery Cycle Life/Cost)

["Peter VanDerWal" <peterv@peoplepc.com>]

> The table also notes "Application and Typical Failure Modes":
> for discharges of less than 20% "Float/overcharge Failure"
> for discharges of 18-38% "Transition"
> for discharges greater than 38% "Cycling Failures"
>
> I am not really sure what they mean by "transition".
>
> So, what do folks think?  It kind of looks like, at least in theory, these
> batteries would last more than 3000 cycles in my usage, or about  4
> years.  That would work out to about 34,000 miles on a battery pack, which
> sounds too good to be believable.  Is it?


Transition probably means that failure was caused pretty much evenly by
charging AND discharging.

As for cycle life, I'll bet these were discharged at pretty low rates
(compared to EVs).  It seems to me (opinion here) that batteries fail
quicker under high discharge loads than they do under low loads.   Assuming
that's correct then I would guess that you might get a few less cycles.

Then again they probably consider the batteries to have reached the end of
their life when they only hold 80% of original capacity.  With your
anticipated discharges you'd still be able to use the batteries until they
reach , oh maybe, 50% capacity.  This would give you quite a few more
cycles.

Over 30,000 miles does sound like a lot, but others on this list have post
figures that high and higher.

Did you get any specs on how badly the batteries sag under EV type loads?