[Coco] Waaaaaaaayyyyyy of topic

[Richard E Crislip]

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.