Subject: FYI....Batterys

From: altavoz <[email-masked]>
Date: Fri, 23 Aug 1996 23:43:44 -0700

A size 27 deep cycle is 100 to 120 Amp Hour ( AH ) and it
will not put out 100 amps for 1 hour ( Trojan T105 is what 
you need in this case ) , it will give 100 AH if you cut down
the amps to something like 5 or 10 ?
A new batt is 65% effecient and takes 154 AH to fully charge
( 100/154=.65)
Its not econo' to discharge below 50% and they need to be rechrged
in hours ( 50% discharge for 12 hours means sulphation and an early
death). 
Deep cycle batts will take 10 amps as they charge thru 13.5 v but
will boil as they reach 13.9 so you'll need to roll off the amps
as volt goes up ( this a gradual thing , not a step).
Fortunately PV panels do the same curve ! So you're getting your
moneys worth . You should pick a panel that peaks ( watts) at 
about 15v. anything higher and you'll operate the panel off its 
max effeciency. Hosfelt and other electronic mailorder have
latching 12 v relays but amps are low so use them only on small
panels in place of diode ( if you're concerned about effeciency
or use Schottky diode )

______End of text  from [email-masked]

---

From: Q Myers <[email-masked]>
Date: Sun, 25 Aug 1996 06:15:34 -0700

altavoz wrote:
>SNIP>
<SNIP>

Where do you get your batteries? Junk dealer?

A new battery should be 85% to 95% efficient.

-- 
Q Myers
http://www.teleport.com/~qmyers
Solar Powered in Central Oregon

---

From: altavoz <[email-masked]>
Date: Wed, 28 Aug 1996 09:02:53 -0700

> A new battery should be 85% to 95% efficient.

_____________________________________
I MEASURED over 160 ah to charge and < 100 ah into a 
10 hour load on a new deep cycle. Manufacturer said he got 65% . 
This is not rocket science ! Any one with a 1% DVM and a 1%
ampmeter can do this test without any significant errors .
Since the readings change so slowly , you get very low data
errors ( check once every 30 seconds )

---

From: Q Myers <[email-masked]>
Date: Wed, 28 Aug 1996 16:56:51 -0700

altavoz wrote:
> 
> Q Myers wrote:
> >
> > altavoz wrote:
> > >
> > >SNIP>
> > > A new batt is 65% efficient and takes 154 AH to fully charge
> > > ( 100/154=.65)
> > <SNIP>
> >
> ammeter can do this test without any significant errors .

I've been living off the grid, with battery power for several years now
and have been using a Trimetric AH meter. I maintain that if your
battery is only 65% efficient, its time to buy a new battery!
-- 
Q Myers
http://www.teleport.com/~qmyers
Solar Powered in Central Oregon

---

From: [email-masked] (Gene A. Townsend)
Date: 28 Aug 1996 17:09:01 -0700

>______End of text  from [email-masked]

Well...then...how did you mess up your measurements so badly?

You must have been charging that sucker at an incredably high rate.

What was your charging rate versus state of charge?

With a "fast charge", 65% charge efficiency wouldn't be unusual.

What is you point here?  Search for the missing details game?

Trying to prove some point?

Reality is already cruel enough in the alternate energy field to have
misinformation spread so rampantly.

No one who knows what they are doing would use that type of battery,
anyway.

Get a good book on lead acid batteries and do some studying.

Gene A. Townsend

---

From: [email-masked]
Date: Thu, 29 Aug 1996 13:53:19 GMT

>> ______End of text  from [email-masked]

Are we forgetting that it takes 14v to charge a battery and the
battery delivers only 12?

the difference in ah going in and the ah going out is due to
overcoming internal losses (battery resistance, heat, etc) when
charging

jim