Battery Charger Overcharge?

[Tom Warner]

Chuck there is a lot of confusing information out there when it comes
to batteries and chargers and I am not advocating that I have the
correct one, just the one I use based on my experience and using the
information Xantrex provides with its charger/inverters. Keep in mind
that we are talking about lead acid deep cycle batteries and 3 stage
chargers and not normal car batteries or standard chargers (battery
boilers) which I have seen installed in many motorhomes including
Bluebirds . And also it should be noted that I am using some
very rough data. For instance we have to put 114 ah back into the
battery for every 100ah we take out when we recharge.

You can use a 25% rate of charge based on the battery capacity based
on the 20 hour rating as you noted as long as you use a 3 stage
charger that does not go over 14 volts (where gassing occurs) during
the bulk charging cycle which Xantrex products are designed for. For
the FC models with four 6 volt deep cycle batteries that is about 110
amps and for the PTs that came with six 6volt deep cycle batteries
that is about 170 amps.

The Heart 2500 that I have installed in my 1985 PT 40 is connected
to six 6 volt deep cycle interstate batteries and they are monitored
by a link 2000. When I normally turn on the generator to recharge my
batteries the link does show between 120-130 amps depending on the
state of charge of the batteries . If I start the engine up I see
over 190-210 amps charging thru the link and thats not good for the
batteries. Have not checked yet to see what size alternator I have
but it is obviously over 200 amps. Xantrex and a few others notably
Balmar saw this problem in trucks and Motorhomes and came out with an
alternator 3 stage regulator which you can either add to the
alternator or get with one of their Link models.

RVs have a special use for the deep cycle batteries, we want to use
them to 50% of their power (ideally) before we recharge them but we
all know we dont live in a perfect world and sometimes they are
discharged lower and thats all right since thats what they are
designed for. They are rated for the number of times they can be deep
cycled. If we pump to much current to the batteries we reduce their
service life but that is sometimes a tradeoff we live with. With
diesel fuel at $3 or beyond to run the generator I dont want to spend
8-9 hours to recharge my batteries with a truecharge 40 when I can
cut it to 1/3 using a 130 amp charger. But then thats just me and
each of you may have a different requirement and ideas.

tom warner
vernon center,ny
1985 PT 40


At 07:35 PM 5/13/2007, you wrote:
>There is a maximum charge rate that you do not want to exceed if you want to
>preserve the life of your batteries. If you have four deep cycle batteries
>6 volt batteries this would be between 10% and 13% of the battery's rated
>20-hour capacity. In the case of a FC with four 6 volt batteries (T105)
>this would be around 40 amps. ANY well regulated charger will charge around
>this rate no matter what its maximum output is. The extra capacity will
>allow for the operation of other devices while the batteries are being
>charged. On our coach since we do not use inverters this need is met with a
>60 amp charger and meets our average demand.
>
>
>
>- Chuck Wheeler -
>
>82 FC 31 SB
>
>Fort Worth, TX
>
> _____
>
>From: WanderlodgeForum@yahoogroups.com
>[mailto:WanderlodgeForum@yahoogroups.com] On Behalf Of Tom Warner
>Sent: Sunday, May 13, 2007 2:07 PM
>To: WanderlodgeForum@yahoogroups.com
>Subject: Re: [WanderlodgeForum] Battery Charger Overcharge?
>
>
>
>Unless you are going to exclusively use a RV park and shore power you
>do not want to use a 40 amp charger in a Bluebird. Again your
>choices should be driven by your individual family requirements. If
>you dry camp at all then you want to recharge your batteries quickly
>and efficiently. Even the FC models have at least 4 six volt deep
>cycle batteries or 450AH of battery power. If you use the 50% rule to
>discharge them to before recharging it would take a truecharge
>40 approximately 5.5 hours to recharge the batteries. With a
>refurbished Xantrex Freedome 458 inverter/charger that furnishes 100
>amps charging and 2000 watts of inverter power it would take
>approximately 2.25 hours to recharge. Price of the truecharge about
>$450
>http://www.xantrex.
><<http://www.xantrex.com/productcart/pc/vi...Category=2>h\
ttp://www.xantrex.com/productcart/pc/vie...Category=2
>8&page=2.> com/productcart/pc/viewCat_h.asp?ProdSort=1&idCategory=28&page=2.
>
>
>Price of the refurbished
>458 $525.
>http://www.xantrex.
><<http://www.xantrex.com/productcart/pc/vi...dproduct=1>h\
ttp://www.xantrex.com/productcart/pc/vie...dproduct=1
>06> com/productcart/pc/viewPrd.asp?idcategory=23&idproduct=106
>Tom warner
>vernon center,ny
>1985 PT 40
>
>At 11:52 AM 5/13/2007, you wrote:
> >Bob, I have had about six truecharge 40+ models and they have not
> >been reliable for me. When they fail the factory told me they are
> >unrepairable. Also they only put out 40 amps, so at night with the
> >lights on, there is not much left over for charging. Other people
> >may have better experience but I'm not buying anymore. FWIW
> >
> >Dan
> >81RB33
> >Jackson, MS
> > ----- Original Message -----
> > From: bloomas
> > To: WanderlodgeForum@
>yahoogroups.com
> > Sent: Sunday, May 13, 2007 10:44 AM
> > Subject: Re: [WanderlodgeForum] Battery Charger Overcharge?
> >
> >
> >
> > ----- Original Message -----
> > From: Pete Masterson
> > To: WanderlodgeForum@
>yahoogroups.com
> > Sent: Sunday, May 13, 2007 8:59 AM
> > Subject: Re: [WanderlodgeForum] Battery Charger Overcharge?
> >
> > .
> >
> > I personally do not care for the old technologically when it
> > comes to battery chargers.
> >
> > If it were me I would look into a truecgarge
> > http://www.xantrex. <http://www.xantrex.com/web/id/3/type.asp>
>com/web/id/3/type.asp
> >
> > You can count on it to keep your batteries at the correct voltage.
> >
> > Are they a little pricey yes.You only get what you payfor.
> >
> > Bob Loomas 1985 PT 36
> >
> > > Hey all,
> > >
> > > I was reading through the posts about battery charger replacement in
> > > an 87, and started to wonder about whether or not I have to worry
> > > about overcharging on the charger in my 78. Is this an issue, or does
> > > it step down as the batteries reach capacity to a trickle charge if
> > > any charge at all?
> > >
> >
> > [Non-text portions of this message have been removed]
> >
> >
> >
> >
> >
> >
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