Dual battery diagram missing

[mork]

Hiya!

I'm trying to rewire my aux battery after switching busses and I don't remember where the wires go. I've searched the history and I get great results except that the wiring diagram is missing and a question mark box is all that appears. Has the link changed? I have the kit from bus depot but I'm pretty sure they're all mostly the same. Did I have a fuse inline previously and where? Any help is so much appreciated!

<3 becky
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What is larger than a mouse? Das Haus! What is smaller then a house? Das Haus!

[germansupplyscott]

it should be something close to this:

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SL

[jgordon]

Thanks Scott,

i was looking for that myself !!!


WOOT

James

[mork]

Yay! Thanks Scott, that's exactly what I needed!
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What is larger than a mouse? Das Haus! What is smaller then a house? Das Haus!

[BUGSTUFF]

Scott,

Thanks for posting this!!!

My buddy's '74 had all the wiring in the engine compartment but it looked like spaghetti. The relay was intact and everything (except one wire) was still connected to the relay. Used the diagram and got everything connected and working again. Just in time for our Rt. 66 Bus caravan next month. His wife is excited that the fridge and the sink will be operational. Yay!
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Kirk

Northeast IL VW Association - www.nivaclub.org
www.facebook.com/nivaclub
Volkswagen Club of America - www.vwclub.org

[BONANZA STEVE]

Does anybody have for early Bay? 68 to 71?
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He who flips me off while passing me in my Bus is not a friend. He who stops to help push my Bus is a friend for life.
1. 1969 Bay Weekender
1 1973 412 Wgn
1 1967 Ford Fairlane Ranchero

[NOVA Bus]

Nice work Scott!
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1977 Transporter / Weekender
- GE engine, L-Jetronic w/ hyd. lifters
- Brown Beige plaid P27 Interior (ED)
http:/[url=http://www.vw-mplate.com/mplate-29638.png]Click to view image
Camper Interior donor:
[/URL]/www.vw-mplate.com/mcode.php?lang=EN&id=721 (M-Code for interior).

[germansupplyscott]

we make one for 68-71 also. it's nearly identical with some very small differences.
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SL

[hazetguy]

ok, it's time for me to install an accessory battery to run my fridge, and i have what i think will be the correct wiring kit. i am still confused on a couple things:
do i just use a regular braided ground strap for the second battery? in referencing a pic i took of an original second battery in a '79 Westfalia, the ground looks like it is run to another source and is not a braided strap. it's just a wire with a ring terminal at the end, grounding to the body, and a white wire running to the other Westfalia stuff.

i have the stock original fridge for a '74 P27 Westfalia, controls as seen in this pic:

i have also referenced the late bay wiring diagram here:
http://i156.photobucket.com/albums/t17/hazetguy/scan1-1.jpg
http://i156.photobucket.com/albums/t17/hazetguy/scan1001.jpg

the kit i have is a Hella kit. 4RA 003 LGE-141 "Single Relay Kit Battery Or Fridge" which contains this relay: http://www.rallylights.com/detail.aspx?ID=944
from what i have gathered, it is a kit from england.
more info here: http://72.167.58.16/community/showthread.php?t=9
the relay has the same terminals as the one Scott lists above. the Hella instructions leave me confused though. "to ensure satisfactory charging, we recommend that no consumers should be connected to the auxiliary battery during charging". so does this mean i can't have the fridge on 12V power while i am driving and charging the battery? that's the whole reason i want to have a second battery so it can charge while driving, i don't want to have to disconnect the fridge while driving.

also, in looking at Scott's diagram, am i presuming correctly that both batteries get charged while the engine is running?

my objective is to have the second battery only powering the fridge (when not plugged in to shore power), and maybe a small electric 12V fan for air circulation inside the bus, for the second battery to be able to be charged while the engine is running (and also the main battery at the same time too), and for the second battery to be isolated from the rest of the bus electrical system otherwise.
is this the way the system works and i am just misunderstanding it?
will i need some kind of isolator/city control like the 76-79 Westfalias use?

i know this topic gets beat to death, and i've read many other threads, but i am still almost totally confused. i just don't want to burn anything up or damage my existing components. also, if the kit i have is incorrect for this application, i have no problem buying the correct kit.

[MrBreeze]

You ain't got squat, it's in Glenn's garage
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-=Rob

WTB: Bay Shore or Queensboro VW Frames

HBB 1984-2009
RW 1943-2011
ER 1964-2023

[germansupplyscott]

the hella kit you have is, for all intents and purposes, identical to the original VW wiring. our kit is the same also, only we think it's a bit better than the original because it uses no wire taps into the alternator harness, we have a splitter and associated pigtails.

you bold text above is correct in the way the system is designed to work and the relay you have will accomplish this.

this type of relay charges the house battery slowly due to the small wire gauges used. this is probably why the hella instructions suggest not having the consumer (in your case fridge) turned on while the battery is being charged. the original westy fridge units consume a lot of power and with the fridge running the charging circuit can barely keep up with the fridge draw.
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SL

[hazetguy]

thanks for the info Scott. i was planning on wiring according to your diagram using the same gauge wiring you specify, not the smaller main wire that come with the kit, and i was in no way going to cut into the wiring harness or use that scary wire tap thing. i was going to make all connections at wire ends with factory splitters and new connectors.

thanks for the charging info, although it bums me out that it is not recommended to use the fridge while charging. this also confuses me too though, because the Westfalia instructions says "the refrigerator should only be operated on battery power while the engine is running, otherwise the battery will soon run down." i'm not trying to argue this point, i am just confused as to how things stay charged/operating when the bus is or is not running. would putting in a 70A alternator help this situation?
i will be installing a deep cycle battery to help with longer "no charge" times.

[germansupplyscott]

if you want faster charging use something like this:

http://www.germansupply.com/xcart/customer/product.php?productid=17589
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SL

[hamid]

HI all

what is the biggest and best auxillary batery I can put on my bus and where do I get it in Southern Cali. thank you in advance for all your help eveyone.

[aeromech]

[WhirledTraveller]

The Hella instructions are overly conservative. The 5 amp draw from the fridge should not significantly impact the ability of the aux battery to charge. A 70 amp alternator also wouldn't help the situation appreciably. The stock system works fine for most people. Even a 1000 amp alternator won't really charge the battery any faster, the charge curve is pretty much set by the internal resistance of the battery and the voltage setpoint of the voltage regulator.

What can help is getting maximum voltage delivered to the battery, eliminating wiring resistance... that's why things like Scott's ACR help. The ACR is more heavy duty and can use heavier gauge wiring, which will pass more current with less voltage drop. Both the Hella relay and the ACR will fully charge the battery, but the ACR with thicker gauge wiring will get you there a bit faster.

Beyond that, the only thing that could charge the battery any faster is a fancy multi-stage voltage regulator, but they start at $300.
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1977 Westy, Automatic. Big Valve heads, CS Cam.

[Skipro]

Is it possible to charge both batteries at once with an external battery charger simultainiously?
I have taken out the charger under the Z bed, and Marr-ed the connections, so I am unable to charge the aux bat with the "shore power" source.

Wondering if i put the battery charger on the starting battery, and run a hot lead from the starting batt to the trigger post on the aux regulator, simulating a "charging" message from the blue alternator wire. If this would act as the normal charge the alternator would create during normal driving operation?

The battery charger would indicate "charged" when both batteries are topped up.


Question # 2.

I have switched the trigger for the radio to use the door buzzer mod (key inserted into ignition without turning, powers the accessory yellow wire on the radio-saves points).
Would it be detrimental to install a switch containing the + from the aux battery, and the + from the starting battery (maybe a 3 way switch, off, on aux, or on start bat) so the radio main constant power source could be switched from the aux to starting battery?
Has anyone done this? does it seem redundant?
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Yosemite Yellow 1975 Westfalia (78 2.0fi)

[WhirledTraveller]

Skipro:

The solution you describe in #1 would work but you have to connect your hot lead every time and don't forget to disconnect it. If you run a hot lead from the start battery to the relay all the time, you will combine the batteries at all times and also run down your batteries from the relay draw when parked.

The solution to this problem is to replace the stock battery combiner system with a "smart relay" or ACR "automatic charge relay" which will combine the batteries when EITHER battery is being charged. To sources are Blue Sea Systems and Yandina. You can just google them. They do away with the need for a blue alternator sense wire and are a simple, elegant solution.

For Question 2, what I do is simply run my radio off the aux battery at all times. There's no particular reason to ever switch it to the start battery.
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1977 Westy, Automatic. Big Valve heads, CS Cam.

[germansupplyscott]

[gatorjos]

I just received on of these Hella Camper Relays, and was a little puzzled by the tiny wire gauges for the charging. I think I'm going to swap the blue/red and red out for some 10AWG. Does anyone know how many amps the relay is rated for? I think my fully discharged 115Ah deep-cycle will take whatever the alternator will give it (45A?), so the 16AWG or so of the current wiring is a joke...
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1977 Westfalia Weekender Berlin "The Kitebus" aka " Colonel Mustard"

Previous romances:
1972 Ghia cabriolet (full body-off restoration -- stolen after five years of ownership)
2004 Passat 1.8T (manual)

http://21stcenturyhobo.com