Date:         Wed, 2 Jul 2003 22:14:38 -0400
Reply-To:     Chris Earl <vw_traveler@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Chris Earl <vw_traveler@HOTMAIL.COM>
Subject:      Auxiliary Battery Installation II: Hawker Odyssey battery,
              Hella relay, Chargetek AC charger (v. long)

Assembly:

For the time being I have posted photos on my Yahoo account. Not sure this
link works:

http://photos.yahoo.com/bc/chartres456/lst2?.tok=bcLVsyRB1fEA_k3W&.dir=/Vana
gon+Battery&.src=ph

This URL needs to be on one line, of course.


1. Preparation

Removed the ground strap from the starter battery.

Removed the driver's seat per Bentley. The four nuts holding down the seat
turntable were removed; the seat track was then lifted and shoved forward
to provide complete access to the battery compartment.

Held the aux batt compartment door open with bungee (duct tape would work).

Cut a 12 x 14" piece of 1/4" minicell foam and a 13 x 6" (approx) piece of
1" minicell foam.

Cut the MDF board to fit the battery compartment, allowing 6-1/2" for the
battery. This was trimmed further later for a tight fit. The idea is for
the MDF to both brace the battery, keeping it from shifting around in the
compartment, and serve as an insulated support for the fuseblock and relay.
There is a need to make a diagonal cut on the right rear corner and carve a
shallow channel for the wires coming in from the dash on the right side. I
also drilled two holes, countersunk underneath, and inserted a loop of
3/16" cord, knotted at the ends, as a handle to lift out the MDF board as
it's being fitted.

There is a cable clamp on the rear wall of the battery compartment that
supports the conduit with the fridge and water pump wires. I removed it and
set it aside. There is a dimple in the wall just to the right and slightly
higher of the original mounting hole, into which I drilled a hole a 1/8"
bit for later re-placement of the cable clamp.

To make access and wiring easier I removed and set aside the screw holding
the refrigerator relay to the frame of the battery compartment.


2. Wiring

My approach was to bring all the wires from outside into the battery
compartment, add whatever terminals were needed, hook everything up, then
connect the batteries.

First I installed the battery charger under the sink in the inside forward
wall of the cabinet. As few people know until they start messing around
with the camper circuitry, the fridge gets its 110V shore power from a
regular household-style outlet on the left side of the under-sink cabinet.
The charger gets the free outlet. I brought the battery charging leads
forward through the opening used by the fridge cable and pulled them into
the battery compartment by the same route.

The charger has two pairs of positive and ground leads, one for the starter
battery and one for the aux batt. The Chargetek charger comes with 5/16"
ring terminal connectors. For my setup I left both ground leads and one
positive lead alone, but I cut the ring terminal off the second red
(positive) wire and replaced it with a crimp-on female insulated quick
disconnect.

I ran the 12 ga, two strand "safety wire" conduit from the battery
compartment to the dash under the carpet, following the route of the
refrigerator power line.  The cable follows the route of the main dash
harness, over the steering column to the main fusebox. The plan was for the
red wire to be connected at the main fusebox to 12V power from the
alternator/starting battery, and for the yellow wire to connect the aux
batt to the loads on Fuse 3.

This operation was a pain, and was punctuated by a lot of sweating and
swearing. I started just forward of the emergency brake, locating the
fridge power cable, and pushing one end back toward the battery box, where
I fished the end in through the hole. I then pushed the other end under the
carpet insulation toward the accelerator, where I was able to grab it
through the hole in the carpet and pull it up into the dash. Obviously this
could be done with separate 12 ga wires but I liked the idea of the conduit
better. It has that extra layer of insulation and its stiffness may have
made it easier to get the wire through the carpet.

At the main fusebox, I stripped back about a foot of the outer layer of
conduit insulation. The yellow wire was connected to a spade lug. I
connected the red wire to a 30A inline fuse holder via a butt connector
(could have soldered it but did this whole job with crimp connectors). On
the other end of the fuse holder I crimped on a female insulated quick
disconnect.

In the battery compartment I stripped back about 6" of the conduit
insulation. O crimped on a female quick disconnect on the yellow wire.
Since the red wire (12V connection to the starter battery) needs to connect
to both the charger and the relay, I used a butt connector to make a "Y"
with two 4" pieces of wire, one 12 ga and one 16 ga. I put a female
insulated quick disconnect on the 12 ga lead (for the relay) and a male
insulated quick disconnect on the 16 ga lead (for the charger).

Made a lead to connect the relay output to the aux batt. I took 12" of 12
ga red wire and put a round lug on one end and a female quick disconnect on
the other.

Made two relay control leads, each using 6" of 16 ga wire and terminating
one end with a female quick disconnect. I left the other ends alone for the
time being.

On the second inline fuse holder, I crimped a #10 ring connector on one end
and a 5/16" ring connector on the other.


3. Installing the battery

I chose an orientation with both posts adjacent to the rear wall of the
battery compartment. This gave the tightest front-to-back fit, and, in my
view, the least chance of a short.

Lined the back and bottom of the compartment with the 1/4" minicell foam.
(Perhaps a battery mat could do just as well.)

Inserted the battery, angling it in underneath the seat platform and then
dropping it in on the foam. It fits very snugly.

Carefully trimmed the MDF board so it jams tightly against the battery and
keeps it from moving laterally. It probably wouldn't have been a bad idea
to add a couple of angle brackets butting up against the battery to improve
the bracing but I didn't do this.

Using machine screws I attached the auxiliary fuseblock to the MDF.


4. Hooking Everything Up

I checked to make sure I'd already removed the ground strap from the
starter battery.

From the perspective of each component there are the following connections:

- Aux batt positive receives three ring terminal connections: a) auxiliary
fuseblock (via inline master fuse), b) pin 87 of the charging relay, and c)
the AC charger
- AC charger goes a) to aux batt positive and aux batt ground, and b) to
starter battery positive (via conduit to dash) and vehicle ground
- Hella charging relay connects to a) starter battery and alternator
positive (pin 30, via conduit to dash), b) aux batt (pin 87), and c) the
two fridge relay control leads (pins 85 and 86).
- Auxiliary fuseblock input terminal connects to aux batt positive terminal
and through the fuses to whatever loads you are going to put onto it. In
this installation I connected the aux fuseblock to the loads on Fuse 3 on
the main fuseblock via the yellow wire in the conduit to the dash.

I made these connections as follows:

Under the dash I connected the fuse holder on the red wire to one of the
positive connections on the left rear of the fuseblock (not easy to find
but I discovered them when I installed my headlight relays). I pulled Fuse
3 and inserted the spade lug on the yellow wire in the lower slot. This was
secured with electrical tape.

In the battery compartment, I connected the yellow wire to one of the
outputs on the fuseblock and inserted a 10A fuse.

Using vampire connectors I attached the two relay control leads assembled
earlier to the fridge relay control wires on pins 85 and 86. I connected
them to the same numbered pins on the battery charging relay.

Connected the female disconnect on the "Y" on the red wire from the dash to
pin 30 on the charger relay. The male disconnect on the Y was plugged into
the female disconnect on the wire from the AC battery charger. (Note the
disconnects were arranged to avoid mis-connecting them.)

Attached one end of the previously assembled 12 ga lead to pin 87 on the
charger relay.

Attached the #10 ring terminal on the inline fuse holder to the input lug
on the fuseblock. If I had felt more concerned about shorts I would have
covered the lug with liquid electrical tape, but I didn't.

Popped off the insulating cover on the brass post on the plus terminal of
the Odyssey battery, and removed the post carefully using an Allen wrench.
I installed the ring terminals from the following three wires: charger plus
wire; wire to charger relay pin 87; inline fuse holder. I replaced the post
and tightened until just snug. The insulating cover was then replaced on
the post.

Removed the post on the ground terminal of the battery using the allen
wrench and attached the ground wire from the charger. Reinstalled the post
and bolted on the battery ground strap.

Using the 8mm bolt and washers, I attached the battery ground strap and the
remaining ground lead from the AC charger to the body of the vehicle using
the pre-tapped hole in the center rear of the seat frame.

Finally, I inserted 30 amp fuses in the two inline fuse holders, and
reattached the starter battery ground strap.


5. Finishing Up:

I tidied up in the battery compartment as follows:

Reattached the fridge relay to its place on the frame of the battery
compartment.

Re-installed the fridge cable clamp: I cut a small hole in the 1/4"
minicell in front of the new hole I'd drilled in the rear of the battery
compartment. I added the AC charger cable with the fridge cable in the loop
and screwed the clamp into the new hole.

To complete the insulation of the compartment I used contact cement to glue
the block of 1" minicell foam into the lid of the battery compartment.


6. Does it work?

- I turned on interior lights. Is the clock on? Yes.
- I checked voltages on starter and aux batt with the ignition off: Both
were about 12.5V
- The engine started. Hooray!
- I checked voltages again. Both batteries were at 13.5V, indicating the
relay had connected the Odyssey battery to the alternator.
- I turned off the engine and plugged the van into 110V AC power. The
charger worked.


7. Options

This arrangement allows me to easily transfer the fridge and water pump
power to the auxiliary battery if I wish, just by moving the quick
disconnect terminals to the auxiliary fuseblock and adding fuses.

To make it easy to install more lighting and a spare 12V socket in the rear
I snaked a 4 ft piece of "split loom" wire wrap (West Marine #1919968) from
the forward cabinet, behind the fridge, to the aft cabinet. Means I only
have to struggle once and now can string wires fore to aft with impunity.

A 12V outlet can be installed just to the right of the fridge ventilation
grill (looking at the stove it's around to the left, in front of the
table), but I'm still debating how badly I want to maintain a "stock"
appearance and avoid drilling a 1" hole in the cabinet. Alternatively, I
may move the 110V circuit breaker inside the "hidden compartment" (how
often am I likely to need to reset it anyhow?) and in its place install a
12V outlet. For utilities in the aft cabin, positive wires go to the
auxiliary fuseblock through the split loom; ground can be connected to a
ground pin used by the 110V wires on the far left side of the hidden
compartment.


8. Observations

- Miraculously everything seemed to work from the start; simplicity (in
concept if not execution) was rewarded.
- The one really kludgy aspect is the connection to Fuse 3 on the main
fuseblock. It works, but it isn't good electrical hygiene. I completely
covered a spare spade lug in electrical tape and stuffed it into the
positive lead at Fuse 3, but one still worries about a possible short
between the two batteries at this point. It's the weak link, and any
suggestions as to how to improve it (and any other aspects of this
installation) would be appreciated.
- If it turns out the 15A relay system is inadequate for charging a deeply
discharged Odyssey, I imagine this wiring setup should adapt fairly readily
to upgrading to a 30 or 40A system with heavier-duty relay and fuses.

Chris Earl
'87 Westy