Date: Sun, 28 May 2000 15:30:07 EDT
Reply-To: FrankGRUN@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Frank Grunthaner <FrankGRUN@AOL.COM>
Subject: Belated Battery Comments - What Fits!
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For some time as I watch the battery and auxiliary battery threads come and
go, I feel the urge to comment about my battery solution with which I am well
pleased. In previous posts I have alluded to my solution, but offered no
details since I was to lazy to lift the engine cover, and couldn't find my
notes. Well, I found my notes and lifted the engine cover, so here goes.
Starting qualifiers: My '82 Diesel Vanagon Westfalia was converted to a 1.8 L
8V Digifant '90 GTi powersource many years ago, with a specific goal of
maintaining the battery area as it was. Therefore, all of my comments are
related to the diesel vanagon configuration. All others have my sympathy, and
I have no clue as to how applicable these steps are to your configuration. I
studied the area beneath the driver's seat and concluded that this was a
great place for a tuned subwoofer. Adds to the "seat of the pants" driving
experience. Works like a charm - details in the archives. I also looked at
the area beneath and behind the passenger seat. Concluded that the underseat
zone was perfect for the beaucoup watts of subwoofer and primary amps. Bolted
them in and never have had a problem (yes, I added a set of small quiet
surplus fans to maintain airflow out through the swivel seal base, and the
controls of the amps are right at the edge of the storage compartment behind
the seat). The remaining area has long (since purchase in '82) been tool
central complete with unused battery jumper cables.
Needs: Lights! Got fluorescents all over and some incandescents in the poptop
area. All needed for reading, game playing and cooking. Also the sound
systems for upstairs and downstairs eat electrons vigorously. The CB is used
sporadically, but the Apple Powerbook G3 does log many hours, as does the ETX
scope drive and CCD camera. Also with my weak link starter problems, running
these auxiliary loads off the starting battery was unthinkable (also run the
fridge off the aux.).
Solution: Two batteries, gargantuan alternator, lots of gauges, switches and
relays along with external battery hookup for charging batteries w/o lifting
the engine cover.
Starting Battery: I put in the biggest GD battery that would fit in the
diesel battery tray. Answer - the current battery is a Champion Silver UF-6.
I long ago changed the battery terminals to side clamp style since the older
high capacity batteries used the upper terminal are for larger capacity.
About 5 years ago the highest capacity batteries started coming out in the
UF-6 style, which had top posts as well as side terminals. I leave the
plastic caps on the top terminals just in case of contact with the engine
cover. The key killer of the batteries is engine compartment heat. As
described in the archives, I fabricated a heat shield (used surplus
multilayer ceramic composite but anything nonmetallic is fine). This built up
like a box on the engine side of the battery, open to the bottom, but flush
to the clamped engine cover. Used the equivalent of the poptop bubble seal -
with bubble seal oriented along the top of the box. This lets cooling air
flow in from the passenger side rear air vent and out the bottom rear while
cooling the batteries. Box connects at the mounting plate holding the coolant
expansion tank and leaves 3 inches clearance to remove the battery, connect
terminals etc. Box is readily removed if more involved R&R is needed.
Mechanics at Wards think its stock. I had the pleasure of listening to one of
their pseudomechanics hassle a Westy owner as to why he had removed the heat
shield! That will really kill battery life, he knowledgeably said. Explaining
electrolyte evaporation.
Auxiliary battery: Well the area behind the diesel battery and behind the
taillight constitutes a great box of similar dimensions to the primary diesel
battery location. As I '83 I began mounting the side terminal batteries here.
Bit costly though because just before each major camping season began, I
would have to replace the battery. Deep cycle discharge of a non deep cycle
battery! Well, I really mean expensive in the sense of time. You have to take
out the starting battery to get at the auxiliary. With time, as I explained
in a pervious post, the Montgomery Wards battery people kept getting
increasingly surly over the 2x per year replacement strategy (probably
waiting for the lawyers to write an exception into the battery warranty
specifically addressed to me!). Anyway, no deep cycle batteries were
available that would fit in the space allotted. Remember, the Optima GelCell
RedTop is not deep cycle. Finally I discovered the Nautilus MegaCycle GelCell
deep cycle marine battery (made by Exide). The NC-24 has dimensions of 10 -
3/16 inches long, 6 - 13/16 wide and 9 - 7/16 high. The specs are: 74 minute
reserve capacity at 20 amp discharge rate, and 130 minutes at the continuous
10 amp discharge test (60% cell voltage remaining), and 550 CCA at 32 F.
Weight is 51 pounds. This battery is marketed by Exide as the Nautilus
MegaCycle or the Prevailer. The battery has a dual terminal setup. I run the
main ground and the alternator charging lines to the automotive type
terminals and the load lines to the wing nut load terminals. Important, for
mounting, I use the battery with top terminals only, and lay it down with
terminals facing the taillight. I do all wiring with taillight removed. There
is a gap of approximately 1.5 inches from the battery wall to the rear deck
flooring. At the rear edge of this compartment I removed a lip of metal that
interfered. Used a hacksaw then rubberized the whole compartment. New battery
cost was around $70.
Update: Since this original install, Optima has come out with several deep
cycle gelcell batteries that will fit this same area. If the Nautilus ever
fails, I'll replace it with one of these. Of course, the Nautilus has been so
reliable that I forgot how I put it in there. The Optima models are the D900M
blue top or the 750S yellow top. The retail on these puppies is around $180.
But a better investment than a $700 spare 9 liter gas can to fit in the spare
tire.
Oh - afterthoughts: Rigged a rubber retaining strap to keep the battery from
shifting about. I use the VW relay approach to switch the battery on and off
the primary alternator load, but I use the puny (sorry) VW relay to switch a
hefty but inexpensive marine relay (rated at more that 100 amps) to control
the actual load. I also use an emergency override to switch in the two
batteries in parallel is I feel the need to smoke the GD starter. Haven't
done it yet, but I keep it as a threat.
Finally, the combination of bigger starter battery, auxiliary battery relays
and heat shield seem to balance the fridge mass on the left hand side. Frame
height difference on the two sides (equalized tire pressures, etc.) is less
than 1 mm!
Hope this helps somebody,
Frank Grunthaner
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