NN said:
Why do you want VRLA batteries? Aren't VRLA, or gel batteries only
used in off road applications?
Anyway here is a paper that challanges the validiyt of the claims for
20 year life
http://www.phlsci.com/VRLA_Catalyst/19-4.pdf
It's my understanding the flooded lead acid batteries are a better
buy, amh/hrs per $$, than any other acid battery, if you are going to
use them for solar storage.
Rush
I am familiar with the article. Those guys are a few miles away from me. I
think they're tied in with C&D Batteries, since they also advertise the use
of a catalyst, at least experimentally.
The evidence is overwhelming that in every category of performance except
one, flooded cells are superior to VRLA. The single exception is charging
rate. In cases where a diesel generator is available for charging, VRLA
accepts charge much faster, meaning that the generator can run for less
time. This is mainly a marine issue, but I do have a portable diesel I want
to use.
But there is a problem with flooded batteries, as I describe in the thread
"NEC compliant battery cabinet???". The construction of an NEC compliant
battery enclosure is a nontrivial issue. Unfortunately, no one has posted a
design that specifically passed NEC requirements. If I built one and it
failed inspection on a pervasive issue, it would be a major waste of effort.
And unfortunately, the Philadelphia climate is cold enough in the winter
that flooded batteries would have to be placed within the structure of my
house.
VRLA's are a more reasonable choice for me than most of you guys because
unlike the typical photovoltaic system, this is intended for emergency use.
For omeone whose primary power is provided by a photovoltaic system, the
fact that cheap Trojans can provide 750 cycles at 100% discharge is a
powerful argument.
In my case, for limited use, ie., if the grid went down for 6 months, and I
used up my 200 charge/discharge cycles, and had to toss the batteries, it
would be acceptable.
