ShopTalk Forums | Aircooled VW Tech & Restoration Help

A while back I was involved in a debate with a guy, and now that we have an electrical section...I feel it would be a great time to bring it up...
He was running four VERY large off-road lights on his rail. He was air-cooled and still running the old generator...Well...we in here all know what this is going to lead to...if the charging system can't keep up with demand...then it can't charge the battery...so the battery goes dead while you're driving...His answer to this problem was to add another battery...and no matter how much I tried to explain why this was not going to help...he would hear none of it....NOW...the reason I bring this up is that I have heard more mention of running another battery to power lights...and I am not talking about a second battery hooked to an isolator, so it would prevent the main battery from dying...but rather just two batteries for more power....I am not going to explain why this will not work...because...apparently...I am no good at explaining it...seems simple to me...but I am not getting my point across....SOOO...maybe you guys can run with this topic and go into detail.

Electricity equates very well with water. A car has a battery (bucket), generator/alternator (fill line) and load(s) (drain line). If your bucket is continually running empty, you can get a bigger bucket (more batteries), however it is a patch, not a repair. The proper repair is to decrease the amount going through the drain (use less lights, etc.) or to fill the bucket faster (get a bigger generator/alternator).

Very nice....

Scott tell the guy with two batteries his bucket has a hole in it, and you can prove it.

MedicTed wrote:Electricity equates very well with water. A car has a battery (bucket), generator/alternator (fill line) and load(s) (drain line). If your bucket is continually running empty, you can get a bigger bucket (more batteries), however it is a patch, not a repair. The proper repair is to decrease the amount going through the drain (use less lights, etc.) or to fill the bucket faster (get a bigger generator/alternator).

How do those Westy kits work then?? Or are they more dubble gum candy..

Is the theory that you charge just one at a time.. then switch over and charge the other?


2nd Generating System
We used to run 3 batteries when I was desert running.. common system used the generator.. then we fabbed a mount for a GM generator...

Why?
Our thought was that we'd only have the bare minimum stuff off the generator.. then all the lights, sound etc on the Optional Generator.

3rd battery?
I'm sure many of us have driven without a charging system.. I've commonly been able to run in day time for about 3+ hours without any generator or regulator.

The Westy double battery system uses one battery for the vehicle (chassis) and another for the camping lights and sometimes the radio. That way, you can kill a battery by using lights, but still be able to start the vehicle.

There are better and easier ways to handle it now available.

Like my pull rig...I have the slide in camper, the winch, the lights in the trailer, etc all hooked to the aux battery. So I can sit without the truck running...use all the electric goodies until the aux battery drains flat...but still start the truck and recharge it.

Here is one example of a method to not use two batteries.

http://www.galls.com/style.html?assort= ... 7&cat=2661

The charging system is supposed to keep up with the demand while running. The battery is for starting the vehicle, running anything while the engine is off and taking up the slack if the demands exceed the charging system.... but only for short term. A second battery will just prolong the inevitable, and unless he is running deep cycle batteries, it is going to get more expensive to replace the batteries then to just upgrade the charging system!

Hey, have him retrofit one of these 250 Amp alternators on there!

Ya know...I had an alt like that...it came in a kit to have an on-board welder on my Jeep.
For your next question...no...it was not all that great....but you could bubble gum something back together good enough to make it back home or to camp.

I am with scott on this one 2 buckets just takes alittle longer to empty out than one

here is a thought , next time you flatten a battery out ....lets say by leaving a big set of driving lights on , then get your vehicle boosted so it will start , after driving for a while .. lets say 5 mins , stop get out and grab ahold of your alt or gen housing you might be startled by how hot it is

So now when you overtax your electrical system current out put capabilities you are shortening your alt life by a large amount because of this increased temp