Re: (ET) charger voltage

[David C Robie <mycroftxx1 juno com>]

Very seldom use the GE charger.  Mainly,  3 50 watt 12V PV solar in
series which gives bout 60 OCV - and here in New England a 2 1/2A  charge
in full sun and a float charge on rainy days.  GE charge I needed a
couple times this yr cause of all the rain made the stuff grow like
weeds, solar has had a traditional 10 day cycle with this lawn but grass
seemed this yr to have a 3 day one.  Another effect of global warming. 
Oh well...

Dave
Weymouth MA





On Fri, 28 Jul 2006 17:20:32 -0400 "David Roden" <etpost drmm net>
writes:
> > New batts are about 6.5 ea.  
> > Average batteries chg to about 6.25 6.3
> 
> Open-circuit, maybe; but if you expect a full charge in a reasonable 
> amount 
> of time, the charger needs to push them to around 7.4 - 7.5 volts 
> (on-charge 
> voltage) with current down around C/50 (4-6 amps for a golf car 
> battery).  
> At lower voltages you essentially have a float charger.  Yes, it can 
> charge 
> the battery, but it could take >weeks< to achieve full charge.
> 
> > Landis controller ...
> 
> I've posted here about this before and I'm not going to get into it 
> in 
> detail yet again.  If you're interested, check the archives.  
> 
> Briefly, as I see it, Harry Landis's device is a battery maintainer, 
> not a 
> charge controller.  If you can use it with any kind of success as a 
> charge 
> controller, it's purely by luck and accident.  I imagine that Mr 
> Landis 
> disagrees with me though. ;-)  
> 
> In any case you won't find one on my batteries.  I don't need a 
> maintainer.
> 
> > Occasionally. people 'equalize' batteries by intentionally 
> overcharging. 
> >  This ain't good for them.
> 
> There's no other way to equalize batteries, unless you have access 
> to the 
> individual cells (I don't know of any golf car battery on which 
> that's still 
> possible, as all intercell connectors are now internal).  If 
> equalization is 
> performed at reasonably low currents, the battery gains more life by 
> 
> avoiding sulfation (proper charging), than it loses from grid 
> corrosion 
> (overcharging).
> 
> > ... gotta build a desulfater ...
> 
> I know this will annoy the "true believers," but I have yet to see 
> any 
> concrete evidence that a "desulfator" does anything significant 
> other than 
> applying a long, slow equalizing charge.  The pulsing nonsense has 
> no real 
> effect ("crystal resonance"???!) and is just an excuse to charge you 
> more 
> money. ;-)
> 
> > Charge em to the point that every cell is gassing.  Then leave em
> > overnite to remove 'surface charge'.  Test em in the morning.   
> That 
> > will tell you where your batts are at agewise.  
> 
> This will work; but IMO, it's more accurate to measure voltage while 
> on 
> charge.  Charge until the on-charge voltage stops rising, and note 
> what that 
> voltage is.  It will fall as the battery ages.  (DV/DT is also a 
> fine 
> strategy for charge control, btw.)
> 
> 
> David Roden - Akron, Ohio, USA
> 
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> 
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