I get free deep-cycle cells ex-power stations and am wanting advice re
charging and maintaining, etc. They are Hoppecke OPzS 600s, and Exide
EPP33 660s (flooded lead-acid cells). When the station batteries get
upgraded to VRLA/AGM/Whatever the old FLA cells become available so I
grab them. The Exides are 15 years-old and the Hoppeckes are ten years
They have been superbly maintained by the power co guys and are in
excellent physical condition. Before decommissioning they are
discharged tested a final time, and I have access to all the discharge
test results and so know which cells are suspect, if any. So far very
few have been not good.
Anyhoo, with a couple of 20A Westinghouse chargers I give them a 2.50
vpc boost for a few hours (they've often been stored for some time -
weeks - before I collect them) until that voltage is reached, then
drop back to a 2.4 vpc equalisation charge for a few hours after that,
then when the cell voltages settle I drop them back to 2.23 vpc. At
this point the SC is 1.250, right where the mfgr specs say it should
The Hoppeckes willl be in two parallel strings of six cells, powering
a 12V system on a mountain plateau, at approx 6,300'. Charging there
will be via 4 x 80 Sharp NE-80EJE PV panels (I'll be adding more as I
can afford to) and a 400W Air-X windgen. I'll supplement that with a
gasoline-powered generator/charger. Loads are very light, seldom
exceeding 10 Amps (it's a small observatory).
The Exides are to be operated in two parallel strings of 12 cells (24V
system) at my home below the mountain. They will power a 1.5kV
inverter for emergency backup, but will be running the load all the
time (2 PCs, a switch, ADSL router, a couple of low wattage CFL lamps,
and maybe a TV so that we can laugh at others who don't have backup
systems when their power fails! <jk>). The home setup will be floated
by one or two of those Westinghouse 20A chargers, which I also get
free from the power co
My reason for operating the house setup as a standby type system is
because the AC mains into the house is very bad, with a lot of
fluctuations, and electrical equipment suffers. The battery system
will operate as a large UPS. I'll add PV panels eventually for
outages, but it's still outside the budget right now, and I can use a
genset to top the cells up during extended outages. Also I've modded
the PCs so they aren't using power-sucking PSUs, amd the CPUs are
older model AMD, which are more efficient (lower wattage/heat
I've followed every bit of advice I've received from the power co
guys, and done a LOT of reading on teh intarwebs, which leads me to
suspect this charging/maintaining regimen is correct, but I've been
wrong before. Do you guys have anything to offer or hints and tips,
etc? I'd be obliged if somebody can explain any errors or omissions on
my part. Like most people, my budget is very limited, and I can't
afford to buy new cells, so these have to last. The plus side is that
they were free and I'll be getting plenty more should these fail too
soon, but I'd still like to take care of them as much as possible.
Cheers in advance for any input.
Dang, I spent so much time describing the system I forgot to ask some
The cell voltages vary by around 0.01 vpc at rest (after several hours
off charge and without load) and up to as much as 0.03 vpc when
charging (but again without load). Should any alarm bells be ringing
there? Most of the cells are within 0.01 volts of each other, but one
or two tend to have the slightly greater deviation from the norm.
Cheers again guys!
Thanks for all the help with this and the TriStar question guys. I
really appreciate it.
It's no wonder renewable energy systems are going nowhere. :-\