Hi,

I have been advised by an auto electrician that the output from the alternator of my 1982 camper is too low at 13.6 to 13.8 Volts to support dual batteries. He has offered to overhaul the alternator before I consider the dual batteries even though I am not having any electrical problems.

I am told by a local VW mechanic is that the alternator is perfectly OK and that is what you would expect from a 1982 vintage camper.

Who is correct? Has anyone been confronted with this issue in the past and what was the solution?

Any advice on how I should proceed with the dual battery install would be appreciated. I will only be running a Waeco 25l frdge, GPS and radio from the second battery.

Regards,
Ian

try
http://www.justkampers.co.uk 

they have a forum that is just for people with campers, they might have the answers to your question.

good luck

Cheers
Dave

Go to a battery place and have both batteries tested (often free), if they are OK put both on a slow charge over night ( each one) to ensure they have full charge.
Double check there is NO drain on battery (nothing running to use power). Double check all cables and connections are clean and in good condition (particularly the power lead from starter to battery, earths battery to chassis and Gear box to chassis).
This is all easy, and not much work involved. Then start up and set to fast idle.
Now check voltage (at the battery), and see if it's higher than before.

Is your camper air cooled? If so, probably the has the stock 55A alternator which is sufficient for most campers, unless you stay put for long periods, or have higher than normal demands on power.
Some had optional 75A alt. but I've never seen one in Oz.

Good luck!

[Edited on 27-1-2005 by Andy]

I have run dual batteries in a Mitsubishi van many years ago with a 55 amp alternator.... I used a heavy duty horn reley to disconnect the auxillary battery when the ignition was turned off.... so the standard battery would always start the vehicle, even if the other battery was nearly flat.....

Your alternator output should be at least 14 volts....
The amperage is there OK but You only have 13.8 volts pressure.... It may work OK.... but clean all the electrical connections.. [with the batterydisconnected] including the earth points plus under the earth strap, I always use a stailess steel earth strap bolt and polish under the strap & where it touched the metal body/chassis.... try to make all electrical connections like they were when it left the factory...
Copper gets contaminated and needs to be cleaned...
otherwise there is some electrical resistance....
Once everything is cleaned up, I think it will keep the batteries charged up OK....
sounds like the regulator may be at fault... do You have an internal or external regulator?
Alternators charge even at low engine revs....


Lee --

That battery voltage is fine.
I used to share an Auto elects workshop and they considered ANYTHING above 13 volts as good.

If you want to spend your money wisely, then purchase yourself a "Smart Relay"
These electronically controlled relays hold the two batteries together untill the battery closest to the cars electrical system drops below a pre-set voltage and then disconnects the second battery.

You wire all your accessories to the second battery and run them to your hearts content safe in the knowledge that you wont flatten the primary cranking battery.
As soon as the primary battery reaches the preset voltage the relay kicks back in and reconnects the batteries together.

A point to remember with the parrallel connected batteries charging back up is that the alternator will tend to "look" at the highest voltage (charged) battery which will be the primary battery and will reduce charging current when that battery voltage approaches the regulated output pretty much regardless of the state of charge of the second battery.
This means that the second battery will take considerably longer to completely recharge after a fair draining.
There are some pretty fancy (and expensive) ways to get around this issue but its hardly worth the bother and expense!
Just so you know!!!

L8tr
E

Thanks for all of the info. I certainly will clean up all of the connections and see if it improves the voltage at the battery terminals. To answer the specific questions my kombi is air-cooled and the regulator is and internal regulator.

One further question if any one has been down this road before, is it worth the expense of a deep cycle battery or should I get just a normal battery? I am planning an extended trip to the Flinders Ranges etc. in about April this year and will be out for about two months.

deep cycle are better as they take discharging better

I've just purchased a couple of 'automatic' battery isolator units from Tandy for $40 each (my price). You'll find them in the Jaycar catalogue for just under $50... check their website.

Gps ,radio and fluoro lights will drain next to nothing. Fridge is another thing. They drain heaps of current. So extended stays try for 240v or at least a solar panel. Have used 12 v when driving keeps everything cold but not when parked. Have got duel batteries just normal ones. If planning long stays no 240 then deep cycle batteries better, they will pick up again unlike normal batteries. Gas fridge is best or a small generator

Hmmm, I've been thinking about that problem too... When I get my new isolator in (working on another project at the moment), I'll try testing the fridge running on 240V through my inverter, off the 2nd battery.

Yes. It is a challenge. I am off to the Flinders Ranges in about a months time for two months and will give a jump start battery a go. At home it lasts about a day before the Waeco says enough is enough and shuts itself down before the battery is flat. Takes about a day to bring the 40Ah battery back up to full charge. I will trickle charge it from the alternator as I travel as well as run the fridge. Naturally if we are on a powered site I will run it on 240 and charge the jump start battery. I will let you know how it all goes.

I have also thought of a small generator as they are getting very cheap, though it does mean hauling extra weight ie. the generator and fuel.

Regards,
Ian

I have just got a kombi that I need to fit out as a camper (its bare at the moment) so I'm interested in the dual battery system. I have also considered a deepcycle battery with an inverter for my waco frig so if you can let me know how that goes Kol I would appreciate it.
As for the generator I have one and tried it out charging the battery for the frig but it takes too long and is too noisy and heavy to cart around.
Perhaps some one knows about solar panels? What size would you need to keep a battery topped up for a waco frig?

We...stole 2 batteries from a excavator (big mutha f*&^ers) put them in our kombi....


No prob at all....

Hi,

I am back and have experienced using the Waeco (25l) during the 2 months away. Would appear that some sort of deep cycle battery with a way to keep the charge rolling in is the way to go. I met other travellers using power panels and they indicated that you can run say a fridge (larger than mine), TV and lights without an issue. I will be investigating the different methods over the next couple of weeks. I also saw a generator in the Grampians that did not make much noise and that could also be an option to recharge the battery.

I have upgraded the alternator to the same model with and external regulator which now gives me 14.1 Volts at the battery. This should be ample to charge a deep cycle battery when you are on the move. I did run the Waeco as a freezer off the old alternator during the trip when we were moving and it was great. The ice in the bottles lasted in the esky for about three days.

I will keep you all posted.

Just some of my past poderings for you to read over!

http://www.aussieveedubbers.com/forum/viewthread.php?tid=38569#pid349602 

http://www.aussieveedubbers.com/forum/viewthread.php?tid=14624#pid101591 

http://www.aussieveedubbers.com/forum/viewthread.php?tid=14626#pid100707 

There was another post just on solar panels, but couldn't find it, do a search though.

I found generators too combersome, none are small enough to store either in engine bay or under car etc, so need setting up each day to run. Also to charge a battery it will need to run for hours, so even a very quiet one becomes annoying after 2 hrs. Solar panels worked well for me, but they too have there limitations.

Any further questions, just ask

I have fitted the dual battery system and am quite impressed. It turned out to be a 120 A/H AGM battery connected to the starter battery via a Redarc isolator. It works extremely well and gives about four days without moving. Takes about one and a half hours to charge from flat either by driving the vehicle or using a smart charger running on 240V (mains or generator).