2 batteries for camping FAQ

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Has anyone succesfully done the "two batteries" thing with a switcher of some sort? I remeber hearing about this before. it automatically switches between the two batteries and keeps them both charged.

thanks,
vince

[bajorek]

Go Westy has something. I found what looks to be a decent one at JCWhitney too

http://www.jcwhitney.com/product.jhtml?CATID=348376&BQ=vw&_requestid=52226

I'd be interested in knowing how it works if anyone has one.

[blackchop65]

why bajoreck ...thanks for that link! just what i been on the search for for my 74 westy. i have dual batts in my bus. one is a deep cycle, other regular 12 volt. just been needed the 12 volt converter so i can run my inside 12 volt lights,etc.

[crofty]

Hey that's a rip! J/K Bus Depot ahs that kit for less than half that price!

Dual Battery Relay Kit, 67-91, for adding a second battery $18.95 1738

www.busdepot.com

[carey blanco]

NOT THE SAME BUT IT WORKS. I GOT MINE FROM busdepot AND IS EASY TO INSTALL , AND IS ALMOST HALF THE COST OF THE whitney .

[bajorek]

Does it look the same as the JCWhitney one- does it have all the same parts? I saw one on E-bay with just the wires and some sort of relay for $30.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?Vi...2418971447

[nodtobob]

it doesn't have all the same parts, has the relay and the wiring, but not the battery terminal posts like the whitney one has. It is easy to install like "carey blanco" said in that post. You can either wire it up for running a fridge or to charge your auxiliary battery if I remember correctly. They are cheap at busdepot now and I think they are on sale. anthony

[bajorek]

I'd like to add a second battery- what kind should I get?
I'd like it as a back up, to run a few fans, and maybe the stereo.

[Adventurewagen]

Get the biggest battery that you can fit in the bus or afford. I have a Group 29 (DeepCycle RV/boat battery) that fit into my bus. The only thing bigger with more amp-hours would be a battery for a golf cart or running more batteries in parallel. You will also need to get an isolator (not a switch). They are about $32 from any store like shucks. If you have an old bus (~75 or so, I am not positive on the exact year) you only need to get a 95amp isolator, but if you have a newer bus then you may be able to use the 120amp isolator (this only affects how fast the battery can charge while you drive). It is dependent on your alternator in the bus. I have a 71 which has the smaller alternator and can only output about 90amps anyway.

Check out this link, it shows a very simple view of how things hook up.
http://www.geocities.com/harald_nancy/images/battery_isolator2.jpg

As for the stereo, you will most likely have to rewire the power to it since it already should be hooked up to the main battery.

Hope this helps

[Aussiebug]

71 adverture - that link doesn't work.

I think you meant http://www.geocities.com/harald_nancy/images/isolator_2.jpg

And for info, the VW alternator is 50 amps, not 90 (although I've seen some aftermarket 75 amps alternators which fit the VW). Or am I missing something?

I agree with the battery size though - you need a high amp-hour deep cycle battery. For those who don't know - normal auto starter batteries have many thin plates inside for high-amp short-duration use - to power the starter mainly, then the gen/alt suplies the car's electrics. Auto batteries HATE being completely flattened and will have a much reduced life if used as a camper battery. For continuous drain, you need a deep cycle battery which has fewer but thicker plates inside, so it can withstand discharging without the lead material (which gets soft when the battery is flat) slumping off the plates.

Golf cart/fork lift/RV style batteries work much better as a camper battery.

Rob
Rob and Dave's aircooled VW pages
Repairs and maintenance for the home mechanic
http://www.geocities.com/aussiebug1970/

[Adventurewagen]

Sorry for the broken link. Neither work above. Here is their main page, that works.

http://www.geocities.com/harald_nancy/isolator.htm

As for the Alternator (Aussiebug), I didn't know if was only 50amps? I never really had the desire to hook up my wimpy voltmeter to it while it was running. I bet its in my manual somewhere, I will do a double check. I knew it wasn't any bigger than 90amps, I guess that it doesn't change anything with the isolator though. You should just get one that can handle a higher throughput than the alternator can supply.

There are alot of batteries out there, I did a good amount of research before getting one because I wanted to get the biggest and best one I could to last me as many hours as possible. I ended up getting whats classified as a Group 29 Deepcycle RV/boat battery from Sears. You can get a Group 24, 27 or 31 battery as well, amp-hours range from about 70 to 125 with those. 29 and 31 usually only differ in dimension and not amp-hours (maybe 10 amp-hours). You can go bigger with a 4-D or 8-D, but it probaby won't fit in your engine compartment opposite your current battery (which is where mine is), and you can go to a golf cart battery but be careful, it may only be a 6 volt battery in which case you would neet two in series!

I am also looking at adding an inverter/3-stage charger, has anyone added one of these? I know RV'ers do it all the time to get max charge while they are running, but use it with their diesel generators as well, which I don't have.

Evan

[crofty]

I think the 90amp alt are in Vanagons.

[Travis H.]

so what is the real advantage of having dual battery's
_________________
- 67 type 1
- 59 panel

[germansupplyscott]

the idea of dual batteries is to allow powered items to operate and not drain your main engine battery, which could prevent you from being able to start the vehicle. when the engine stopped, the 2 batteries are isolated, when the engine is running, both batteries are charged by the alternator.

dual batteries were standard equipment on campmobiles with electric refrigerators. it allows you to run the fridge with the vehicle parked. on a campmobile with factory dual batteries, the only thing powered by the 2nd battery is the fridge. a large deep cycle battery fully charged will run the fridge for about 8-10 hours.

some people extend the factory wiring and use the second battery to power an inverter for 120v appliances like TV's or PS.

i make a dual battery kit that is patterned exactly on the factory installation. it has factory-style crimped terminals and is shrink-wrapped and sized exactly to fit. all the other dual battery kits available are just some lengths of wire, a relay and loose terminals. other kits require you to cut and crimp wires, ours can be installed in minutes and is a much cleaner solution.

whichever relay kit you use, there will be extra distribution wiring needed to make the 2nd battery power other appliances like inverters or auxilliary lighting.
_________________
SL

[WileyVW]

I have duals (optima red/ optima yellow) in mine, I rewired all of the interior lighting and cigarette lighters front and rear to run off the rv battery fuse panel, 300w amp, 12 pack cd changer, and a switch for the radio to run off rv when parked. Whichever kit/relay you use wire a female cigarette recepticle in the engine compartment for a solar panel charger. Get one of the ones off ebay($10) they use in jap or german delivery lots, it will keep your rv battery up effectively on sunny days , I plug one in front window and lay one on top of hatch. I run a 12v fan and little color tv, and a laptop with plenty of power.

[WileyVW]

http://www.keithandsylvia.co.uk/tech%20pages/splitcharge.htm

[WileyVW]

check this link

http://www.germansupply.com/xcart/customer/product.php?productid=16766

[Dead 1]

[WileyVW]

I connected the female cigarette recepticle directly to the positive terminal and grounded to the chassis or you can ground on battery negative terminal.

[OB Bus]