[Coco] Waaaaaaaayyyyyy of topic

Gene Heskett gheskett at wdtv.com
Fri Nov 7 13:52:18 EST 2014


On Friday 07 November 2014 09:46:18 Richard E Crislip did opine
And Gene did reply:
> On Thu, 6 Nov 2014 11:38:11 -0500
> 
> Gene Heskett <gheskett at wdtv.com> wrote:
> > Hi all;
> > 
> > Is there anyone here that knows ALL about the care & feeding of
> > lead-acid batteries? I have considerable experience with them in car
> > & truck sizes, but the one in my 20kw standy generator would be
> > adequate for a 2CV in warm weather only.
> > 
> > I appears that Generac has equipt their 20kw nat gas standby with a
> > trickle charger that IMO is way too beefy, holding it to 13.88 or .89
> > volts.  That is sufficient to make any battery gas and use up its
> > water way before it should.  Ideally, and in my experience if the
> > holding charge is correct, no gassing occurs, and they can go 6 to 10
> > years w/o a drink of water.  I once made a switchmode voltage
> > regulator for a car battery that when adjusted, worked well.  It
> > could start a tired 63 tin indian wagon at -37F just like it was a
> > warm spring day, and it, the alternator and battery were used on the
> > next 4 cars I owned over a period of 8 or 9 years, and I never had to
> > add water to that battery, despite the fact that a startup on a cold
> > morning would bang it up to about 15.9 volts at nearly 100 amps from
> > that HD alternator, but it faded to cool spring settings in about a
> > minute, then to warm summer settings as the engine compartment warmed
> > up, so the overcharge out-gassing was very close to zilch.
> > 
> > I applied that same theory to a pair of 220AH 12 volters used as 24
> > volts by switching them into series to start the 150kw Cummins 335
> > powered standby generator at KXNE-TV in NE, and determined that a
> > 1000 ohm series R from the line powered charger was way too low, and
> > while I don't recall the actual resistor I used to limit it
> > maintenance charge, I do recall that I was down to around 7 milliamps
> > for the 2 batteries in parallel to keep them from outgassing while
> > still maintaining around 13.65 volts for long periods of time.  When
> > I went down the road to the next job, those batteries were then 7
> > years old and I had added water once, about 2 weeks after I
> > discovered that charger was burning them up.  And likely burn up the
> > 3 year old batteries I had to replace.  And they were still turning
> > that Cummins hard enough it fired on the first cylinder to pass tdc,
> > so start time to 1800 rpm and back on the air was less than 4 seconds
> > from a power failure.
> > 
> > Now this Generac has gassed about 10 to 12 oz per cell out of an 81
> > AH, 575 cold cranking amps battery in something under a year.  Not
> > enough to expose plates (that FWIW, is very bad for the batteries
> > health & well being), but enough to trigger a check battery warming
> > on the control panel.  So I filled it with distilled, and reset the
> > alarm.  And logged it.
> > 
> > I guess my question is how do I get a suitable LART to convince
> > Generac their charger circuitry is junk?
> > 
> > Cheers, Gene Heskett
> 
> 8-))) Yeah, I blowed up my little brides motorcycle battery that way
> <sigh>. Well it really didn't blow up, it just died the horrible arid
> death of having its water vaporized... twice... thrice maybe, anyway
> she now has a gel battery.

Most motorcycle charging circuits are very rudimentary, and will kill the 
gelcell way prematurely too.

Unless you want to design a voltage regulator that can function with an 
alternator with a PM rotor.  That will need kilovolt rated hexfets and 
very good varnish on the stator coils because at full song, the open 
circuit voltage approaches a kilovolt for a Honda 350F at its 11,500 red 
line.  That was in fact the only bike I ever had that actually had a 
regulatable alternator setup.  Worked well, batteries could last a couple 
years & 50k miles.  And it was a strong enough alternator that it was 
happy as can be even when my high beam switch brought up a couple 55 watt 
each H3 powered driving lights on each side of the bar mounted fairing.  
My much later & newer Suzi GS-1000-G had a windjammer clone which I'd put 
a CPI headlight in with an off road only bulb, 140 watt high beam, 100 low 
beam, but the battery was slowly being discharged when the high beam was 
on.  My theory is that one is not going to hit what you can see.  Both of 
those setup's did light up the road in front of me nicely. ;-)

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>
US V Castleman, SCOTUS, Mar 2014 is grounds for Impeaching SCOTUS


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