Date:         Wed, 5 Aug 2009 13:14:42 -0700
Reply-To:     mark drillock <mdrillock@COX.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         mark drillock <mdrillock@COX.NET>
Subject:      Vitrifrigo trip results, wiring, battery life, charging issues,
              etc
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

Anne and I just returned to San Diego from a 3 week camping trip in the
PNW area. Just before starting out I installed a Vitrifrigo in place of
our working Dometic 182A. Due to time constraints I pretty much slapped
it in and hoped for the best, making no changes to our existing aux
battery setup other than new Group 48 batteries for both starting and
aux positions. I realized this rushed install might bite me and
eventually it did. I also brought one of those battery voltage
display/alarms that plugged into the cig socket, planning to wire it
directly to the aux battery at some point since it gave lower than true
readings while plugged into the cig socket powered by the aux battery.
After about a week on the road I knew I would HAVE to do something to
improve the battery charging. The battery voltage would drop lower and
lower each night, rising some of the way back up during driving each
day. Finally one night the fridge stopped running because the battery
was too low.

I stopped at that retail giant we love/hate and bought a set of 8 gauge
  battery booster cables and a roll of solder as well as a pocket butane
torch. I stopped at a NAPA and bought a pack of ring terminals, 5/16"
for 6 gauge wire and an extra 8mm nut and washer. Then we headed off to
camp where we were meeting friends at the SyncroSafari near Mt St
Helens. That night the battery voltage again dropped too low, though we
had driven for several hours during the day. I had to fix this and soon.

As a test step I cut the giant battery clamp off one end of one booster
cable and crimped on a ring terminal. Then I attached it to the
alternator stud using the extra nut and washer. I ran the cable on the
ground around the driver side of the van, extending it with the other
cable so it would reach the battery under the driver seat. First I
started the engine and revved it a bit to get a voltage reading at the
cig socket. Then I connected the far end booster cable clamp to the
positive post of the battery. The voltage reading jumped by .7 volts, a
good sign, and I could hear the alternator belt chirping a little under
the load, another good sign. I let the engine run a few minutes and the
voltage slowly increased as the batteries charged. Even with two 12 foot
booster cables connected end to end there was enough increase in
charging current to make a huge improvement at the batteries. Time to
make a more permanent fix.

I borrowed a 1/2" battery powered drill and a grommet from some Syncro
friends and installed the new wire. I cut the booster clamps off, put a
ring terminal on the battery box end, drilled a hole in the bottom of
the battery box, installed the grommet, pushed the cable down through
the hole and put the battery back. Under the van I routed and zip tied
the cables into place, working from each end of the vehicle until the
cables reached each other in an easy to work in space. Then I cut off
the excess length, stripped and wove the copper strands together, and
soldered the joint with a small butane torch. A little electrical tape,
and all done.


The bottom line of this is that the nightly draining of the aux battery
by the Vitrifrigo brought to the fore an existing weakness in the
charging path. Even driving for 4 or 5 hours in daylight did not
sufficiently recharge the deeply drained battery. The addition of a new
8 gauge wire from the alternator to the separator relay corrected this.
We had no further problems with the battery voltage dropping too low
during the night and the voltage came back up higher and much quicker
while driving.

As to replacing the propane capable Dometic with the electric only
Vitrifrigo, the jury is still out. The fridge is nicer in every way but
will need a larger battery capacity installed before it can be used for
more than a day or 2 without driving.

Anne and I have since talked about various additions to help out the
battery capacity. We noted that virtually none of the campsites we
stayed in would have worked with a solar panel. I may still install one
for our Baja trips as there is plenty of sun there on the beach.

Mark