Date: Wed, 2 May 2012 17:41:40 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Another Monster Battery Option For Stock Locations-Charging!
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One of the advantages of AGM type batteries is their extremely good "charge
acceptance". The work very well in float charge applications. While multi
stage chargers seem like a necessity they are really only needed on a
periodic basis. The work on voltage/current sensing and the characteristic
of batteries during the charging process. As such in order for them to
really work the battery-charging circuit cannot be connected to any load,
especially and load that varies. Also, for AGM batteries many chargers will
go to a 16.5 or higher peak. Say goodbye to many light bulbs. Chargers that
are designed-approved for RV use will usually peak out at 14.5 volts and
from experience even that is too much for all those little indicator and
halogen lamps in my motorhome.
Since AGM batteries tend to be expensive, part of the usage plan has to be
to extend their life. It is very important to limit cycles, avoid high
temperatures and sudden temperature changes. Most AGM failures are the
result of the electrolyte venting-drying out in one or more cells.
Probably the ideal float charge is around 13.8 volts. This will keep things
near or below the gassing stage. If you go near or above 14.2-14.5 volts
extended drives can cause some positive plate corrosion. Consider that each
time you "top off" the battery to this higher voltage you have "cycled" it.
For example, you driving and the battery is charged. You stop for an hour or
so to rest get some lunch. Your listening to the radio, or using your
laptop. Whatever. Yu then go drive again, your smart charger or voltage
regulator put that extra umph in after the bulk charge. Yes you have just
used one of the 300-500 cycles that AGM may give you. We make it a practice
that batteries used for opportunity charge should only go above 80% once a
day at most. AGMs tend to last the longest when used between 50-80% stat of
charge with periodic maintenance charges.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Derek Drew
Sent: Wednesday, May 02, 2012 2:49 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Another Monster Battery Option For Stock Locations
Group 27 is a great size to go under the driver's seat. That's the size I
always used in the past. The only thing is that according to my tests, the
Odyssey AGM batteries really are better than regular batteries, and the
Sears licensed Odysseys may just be the best batteries in the world of their
type. My tests were heavy load tests using load testers and were later
coorborated by other tests I found on the Internet. The NC-27 size is
normally available in a configuration that fits well under the front
driver's seat best if it is a normal vented lead acid battery. But I found
that this yields too much problems with battery acid coming out of the NC-27
vents, at least with the lead acid version. The AGM version of the NC-27 is
less desirable because it sticks up a little higher in the key area where it
might hit the driver's seat swivel so I avoided that. If the
NC-27 AGM Odyssey has the same amount of amp hours and reserve capacity as
the PM-1 battery I used, in an AGM version, then I wouldn't be surprised if
the NC-27 would be an easier fit and preferable to the PM-1 battery I used.
But that's a lot of ifs. I might have got stuck because I did not find a
quality AGM version of the NC-27 in a deep cycle design. I did not want a
lead acid traditional venting version of the NC-27. The PM-1 Sears battery
is indeed longer than will fit by dropping the battery into the Vanagon
driver's side stock battery tray. In order to drop it in there, you must
remove some metal from the area to the right (passenger's side) of the
battery tray under the driver's seat. I found that I could remove enough
metal, but leave plenty enough there, to fit the PM-1 battery without having
to do any welding so this is a metal cutting operation only. I then
reinforced the area with bent metal bolted back in, though I doubt the
reinforcement was really needed. In order to fit the PM-1, you have to
approach the problem by saying that you will widen the battery tray on the
passenger side of the tray and have a demonically inspired destructive
intent as you hold a sawzall or other cutting tool. After you have widened
the battery tray, you will discover that it was a relatively trivial
operation, and "major"
only in terms of the mental gymnastics required to realize that it is
possible. The PM-1 battery lists for the same cost as the Lifeline group 27
batteries that you bought. If the Lifeline NC-27 batteries have the same
specs in reserve capacity and amp hours as the Sears
PM-1 battery, then I recommend the NC-27 batteries (in an AGM deep cycle
version) instead of the PM-1 battery I got. If the PM-1 has better specs in
amp hours and reserve capcity, then I'd do the PM-1 again. After checking
about 10 times in a detailed manner, I determined that AGM batteries do not
need to be in a sealed box, and in fact, are safer without one, especially
if you are tuning your charge regulator from the automotive alternator to
have the recommended charge voltages as Odyssey recommends for their AGMs. I
did not use a sledge hammer. The PM-1 battery protrudes upwards, as does an
NC-27 battery, higher than a group 41 battery. But because no special
battery box is needed, and rugs with covering wood or metal structuring of
the lid may be configured to hide the battery entirely, I felt that on the
driver's side the horror of having a battery stick up is mostly
psychological before the job is done, because after the job is done you
cannot tell, and the westfalia seat swivel can still be made to function as
normal by trimming of the metal along the rear edge and/or right rear corner
as neccessary in order to allow the swivel to function as normally. I cannot
think of any better use of the space behind the driver's seat than to have a
battery protrude up there (and then be cosmetically covered) so long as the
seat swivel can still function to 90 degrees, so i am a big fan of using
either of these two batteries at that location. The one thing you would NOT
want to do is to put either of these AGM batteries into a sealed box at that
location..... they do have *some* venting even if it is minimal. Instead,
just mount them to have air ventiliation, and then make sure that the
voltage regulator is doing what it is supposed to do. In this case, there
will not be sufficient hydrogen buildup inside the vehcile to be material to
humans and their stuff, yet the small amount of hydrogen buildup that does
occurr will have someplace to go rather than be trapped in a sealed box
where it could turn malevalent. I advocate the use of AGM batteries for
Westfalia, so custom tuning of any 3-stage regulator to AGM charging specs
would be what the doctor orders unless the 3-stage charger is already set
for Odyssey AGM specs. I did not immediately see which charger at
<http://www.powerstream.com/lead-acid-charger-Catalog.htm>http://www.powerst
ream.com/lead-acid-charger-Catalog.htm
was the candidate one for Vanagon/Westfalia use. The idea of a 3-stage
charger which would take a 12V input and then output 12 volts 3-stage
certainly sounds elegant and interesting so I'd like to see which unit does
that. But still, the most efficient method would be to have the voltage
regulator do the 3 stage charging at the vehicle alternator rather than have
a secondary voltage transformation operation being undertaken. As I said
earlier, with respect to battery fitting, what seems like "major mods"
before you fit a battery may not seem like "major mods" after the job is
done. I don't feel like my method involved major mods now. Among the keys to
the operation was grinding all areas to bare metal, and then the use of
Eastwood's best and most advanced Extreme Chassis Black chassis primer and
paint. I used the very best of the Eastwood's topcoat paint (comes in a
paint can and says Epoxy or something similar) rather than the rattle can
Extreme Chassis Black spray paint that is listed as almost as good, and I
was very pleased with the results and would do that paint again. If your
NC-27s have 100 amp hours, Karl, then just check the other specs such as
reserve capacity to make sure that these other specs measure up to the PM-1.
If they do, then proceed with your NC-27s. If they don't, then you can
upgrade yet again if you like to the PM-1. In the discussion above, I used
the phrase "NC-27" to mean "group 27." I actually have no idea what the
difference between the two phrases may indicate.
At 10:37 PM 5/1/2012, you wrote:
>Derek, a couple questions and thoughts:
>
>This battery is listed as 13" long. Vanagon battery boxes are 12" long.
>If it fits with no use of a sledge hammer on the sheetmetal, then Sears
>has miss-stated the size number - it would be a group 27. 'Fits' would
>mean in would be totally enclosed in the factory box and not protrude.
>It appears that it would protrude 2.5", as it is listed at 9.5" tall.
>
>I have a pair of Lifeline group 27 deep cycle batteries ready to
>install in my 'big trip' rig - one of the industry's leading brands,
>cost was $270 each (local distributor) and are 100 a/h. These measure
>in at 9.25", but can get away with 9" if you remove the bolts in the
>posts - has posts with threaded centers. I will be modifying the boxes
>to keep them totally covered and away from the seat swivels. My second
choice would be Trojan.
>
>Karl
>
>
> On Tue, 1 May 2012 12:53:11 -0400, Derek Drew
> <derekdrew@DEREKMAIL.COM> wrote:
>
> >I chimed into the thread at
> >http://www.thesamba.com/vw/forum/viewtopic.php?p=6013002#6013002 the
> >following information.
> >
> >I am probably among the first to have fit such massively long-lasting
> >and powerful batteries into the front two underseat locations so I am
> >passing it along that it can be done:
> >
> >Derek wrote, in the thread:
> >
> >I installed under the drivers seat the Sears Platinum deep cycle
> >PC31, group size 31, similar in size to Odyssey PC 2150. This battery
> >has 205 Reserve Capacity, unlike the group size 65 / PC1750
> >batteries, which have more like 135 reserve capacity. The group size
> >31 also beats the group size 65 with 100amp hours vs. 68 amp hours
> >for the Group 65. The front seat still swivels. The battery sticks up
> >higher than it normally would, but is hidden behind the grey rug. In
> >order to do this installation, you have to trim the corner of the
> >seat swivel (which doesn't look bad) and also trim some metal from
> >the area under the driver's seat. Would I do it again? Yes.
> >
> >The battery under the drivers seat is Sears Item# 02850131000 Model#
PM-1.
_______________________________________________
Derek Drew
Washington DC / New York
derekdrew@derekmail.com
Email is best normally but...
PHONE: 202-966-7907 (Call the number at left normally) (alt/cell for
diligent calling only): 703-408-1532
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