Subject: Re: Battery power

From: [email-masked] (Mike Prine CIRT)
Date: 27 May 1995 15:17:05 GMT

DICK MCDUFFIE ([email-masked]) wrote:
: I'm looking for some real life experiance from people who live off battery
: power, PV or generator charged. I'm using only 4 6V batterys (T-105 type)
: in 12V config. and 116 watts of PV. (I'm still on the grid, just checking
: feasibility for next (remote) home). How often do you use the hydrometer,
: or are digital meter readings enough to determine when to start/stop gener-
: ator charging? How fast do you charge the batteries, your charge rate(back-
: up not PV) per 100AH of battery bank? I know the big Trace inverter has a
: charge option but 100A sounds like alot for my 435AH bank.I'm in the market
: for an inverter, does anyone use anything but Trace? I only need an 812, I
: have an old Heathkit 200 watt inverter that is fine except it draws 1.75 A
: with no load!It runs a 25" color TV and a couple of compact flouresents OK.
:                        Thanks,
:                           Dick

	Well while I can give you many of the answers you are looking for 
I would recommend a subscription to Home Power Magazine, PO Box 520, 
Ashland Oregon 97520, 1-916-475-3179, you can get some back issuses and 
they have a CD that has issues 1-35 plus other neat stuff. Ok enough 
sales pitch.
	I have been into PV for just over 3 years now on a serious basis.
Our house gets about 1/2 of it's electrical needs satified from PV with
the Grid serving as a backup generator. Deep cycle lead-acid batteries
should be charged/discharged at a C/5 or lower rate. If I recall correctly
the T-105s are about 125AH per battery, since you have to tie 2 in series
to get 12 volts this leaves you with a 250Amp Hour bank at 12 Volts. So
for a 250AH bank that is 50Amps in or out. C/20 would be better at
12.5Amps but probably not practical for you. Most of the Trace inverters
have an adjustment to set the max charge current. My 2012 runs from 0 to
60 amps and I feed 55+ Amps to my 1760AmpHour battery bank. Many folks
recommend skipping the builtin charger option and buying a seperate
battery charge for reasons of increased reliability but I haven't had any
problems yet.
	Now while I am quite happy with my trace inverter, If you don't 
have any large motors you need to run you might want to consider one of 
the smaller types like PowerStar, StatPower or others. They are smaller 
and have lower noload current drain. I have a 100watt TripLight inverter 
that falls in the same catagory as you HeathKit, it is a squarewave 
inverter, great for lights and small electronics but death to motors and 
they have a very high standby load.
	Battery maintiance. This is where the black magic starts. While
general rules exist, every system is unique and you have to watch it
closely to find out how it really behaves. It is especially true durring
the 1st year that you need to be conservative so you don't end up with
dead batteries while you are learning. In my case I try to run and
equalize charge once a month and check the water and do a hydrometer check
once every 3 months and log it in my book so I can spot trends if any. 
Once a week I switch the house back to grid power and let the batteries
come up to equalize voltage but I don't let them stay there long, I just
use it as an indicator that they are fully charged. You can get all sorts 
of meters exist to monitor your system but most folks use a simple 
voltage meter.
	Good luck.
	
 --
I get most of my electricity, at home, from the sun. | Bitnet:   mikep@unmb 
It's a hobby, who cares if it's cost effective!      | Internet: [email-masked]
University of New Mexico in Albuquerque New Mexico, USA
2701 Campus Blvd NE 87131-6046 USA     Phone: 505-277-8135 | Michael L Prine

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From: [email-masked] (E P Searl)
Date: Sat, 27 May 1995 22:35:44 GMT

[email-masked] (DICK MCDUFFIE) wrote:

>I'm looking for some real life experiance from people who live off battery
>power, PV or generator charged. I'm using only 4 6V batterys (T-105 type)
>in 12V config. and 116 watts of PV. (I'm still on the grid, just checking
>feasibility for next (remote) home). How often do you use the hydrometer,
>or are digital meter readings enough to determine when to start/stop gener-
>ator charging? How fast do you charge the batteries, your charge rate(back-
>up not PV) per 100AH of battery bank? I know the big Trace inverter has a
>charge option but 100A sounds like alot for my 435AH bank.I'm in the market
>for an inverter, does anyone use anything but Trace? I only need an 812, I
>have an old Heathkit 200 watt inverter that is fine except it draws 1.75 A
>with no load!It runs a 25" color TV and a couple of compact flouresents OK.
>                       Thanks,
>                          Dick
>For Marge:
>[email-masked]

you might look into prowatt inverters by STATPOWER of Canada. They are
low cost and have worked fine for me.

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From: [email-masked] (DICK MCDUFFIE)
Date: 26 May 1995 03:20:41 -0500