| Battery charging confusion [message #104942] |
Wed, 03 November 2010 15:25  |
jayrabe
Messages: 509
Registered: June 2009
Location: Portland, OR
Karma: 0
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Senior Member |
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Still confused about battery charging. I'm persuaded by Handy Bob that we should follow the battery mfr recommendations and push in 14.8v for an hour or so before we float at 13.6 or so. Problem is that I can't find any adjustments on my Iota or in the documentation to allow that kind of output, or any mention of that as an optional output mode in any other brand charger either.
Does anybody have their chargers set up for 14.8? What brand/model charger?
Thanks,
J
76 PB
Portland, OR
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| Re: [GMCnet] Battery charging confusion [message #104950 is a reply to message #104942] |
Wed, 03 November 2010 15:44  |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
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Senior Member |
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Most of the "smart " chargers do it like this
http://www.gmcmhphotos.com/photos/showphoto.php?photo=17533&cat=4507
or
http://goo.gl/33fiy
some do not have the equalizer mode, but that is more of a "feature"than a
necessity
I am sure your "smart charger" is just fine (especially if you have a
combiner ;>) and the buzz box is gone, as the slides talk about.
gene
On Wed, Nov 3, 2010 at 1:25 PM, Jay Rabe <jayrabe@hotmail.com> wrote:
>
>
> Still confused about battery charging. I'm persuaded by Handy Bob that we
> should follow the battery mfr recommendations and push in 14.8v for an hour
> or so before we float at 13.6 or so. Problem is that I can't find any
> adjustments on my Iota or in the documentation to allow that kind of output,
> or any mention of that as an optional output mode in any other brand charger
> either.
>
> Does anybody have their chargers set up for 14.8? What brand/model charger?
>
> Thanks,
>
> J
> 76 PB
> Portland, OR
>
>
>
> _______________________________________________
> GMCnet mailing list
> List Information and Subscription Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
-------
http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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| Re: Battery charging confusion [message #104969 is a reply to message #104965] |
Wed, 03 November 2010 17:39 |
idrob
Messages: 645
Registered: January 2005
Location: Central Idaho
Karma: 0
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Senior Member |
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| Ken Burton wrote on Wed, 03 November 2010 15:15 |
| jayrabe wrote on Wed, 03 November 2010 15:25 |
Still confused about battery charging. I'm persuaded by Handy Bob that we should follow the battery mfr recommendations and push in 14.8v for an hour or so before we float at 13.6 or so. Problem is that I can't find any adjustments on my Iota or in the documentation to allow that kind of output, or any mention of that as an optional output mode in any other brand charger either.
Does anybody have their chargers set up for 14.8? What brand/model charger?
Thanks,
J
76 PB
Portland, OR
|
14.8 is a little high. Normal charging is between 13.8 and 14.2. You can get by at 14.8 for a short while IF the battery is cold and depleated enough. If you do not know the state of charge on the battery and have no way to monitor the state while while charging, I would not go that high. There is really no advantage to going that high other than an initial quicker warm up and slightly quicker charge.
You are going to have to drop back to a lower voltage (13.6-13. once the battery starts gassing or gets too warm. When it is fully charged you will need to drop every further to about 13.2 as a maintenance charge of about 13.2.
Note: On a fully charged room temperature battery you can go to 14.4 for very brief periods like 15 minutes or so without hurting it.
I would not go to 14.8 unless you are going to sit there and watch it while it charges.
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I would agree with Ken. Also remember that the PD or other "smart chargers" are not temperature compensated and charge voltage really should be set depending on temp of the battery. Good solar battery charge controllers have a probe that is fastened onto the battery bank so it can compensate for the temperature of the string. It is just one more variable to consider. There is no "perfect" voltage for charging under all conditions. Ken's numbers are a good compromise though.
One other thing that is not mentioned very often. As a battery ages, it, as a normal thing, takes more water. One way to tell if your battery is becoming long in the tooth is by the amount of water it takes, even with a good 3 stage battery charger like the PD. Old + seeming low capacity + needs water often = good sign to replace.
I believe that much of the "buzz box boils batteries dry" statements are involve old batteries which are on their last legs anyway. Now I am not saying that the Buzz box chargers are good, but I think they were somewhat better than it has been reported here in the forum. I love my PD units, but the old buzz boxes were not horrible in my opinion, just technology has passed them by.
Rob Allen
former owner of '76 x-PB
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