This topic can get complicated real quick. The simplest approach is to use the existing relay and wiring as much as possible. This approach can give adequate results if your needs are small and your wiring is in very good shape. First you must determine if the existing wiring has enough voltage available at the relay to even charge a second battery while you are driving with the fridge running. Measure the voltage at the heavy wires to the relay, with the engine RUNNING and the fridge TURNED ON to 12 volts DC setting. If you don't have at least 12.50 volts at the existing relay under these conditions then drop the idea of using the simplest approach. You will need to run a more direct charging wire to get a high enough voltage to charge the second battery. 13.50 volts is more like what you want the second battery to see. I consider the relay kit sold by TBD to be a bit of a joke but it works and is safe. Better to use a slightly bigger relay and heavier charging wire IMO. The kit sold by TBD and other places is sized right for 60s and 70s buses but your 88 has a much more robust alternator and electrical system. VW used a much more capable second battery charging arrangement on those Vanagons that came with second batteries so I would duplicate that later stock method. Mark John Graham wrote: >I have an 88 Westfalia with the full refrig, stove etc package. I've >finally decided that it would be nice to have a auxillary battery to >power things when parked. I have found that it's really easy to start >the refrig on gas if it's been running on AC or DC for a little while >so that the 'chimney' is warm and drawing a draft. Being able to cut >it on for a short on the battery while sitting still would be a nice >feature..... > > |
Please note - During the past 17 years of operation, several gigabytes of
Vanagon mail messages have been archived. Searching the entire collection
will take up to five minutes to complete. Please be patient!
Return to the archives @ gerry.vanagon.com
The vanagon mailing list archives are copyright (c) 1994-2011, and may not be reproduced without the express written permission of the list administrators. Posting messages to this mailing list grants a license to the mailing list administrators to reproduce the message in a compilation, either printed or electronic. All compilations will be not-for-profit, with any excess proceeds going to the Vanagon mailing list.
Any profits from list compilations go exclusively towards the management and operation of the Vanagon mailing list and vanagon mailing list web site.