Auxiliary battery question?

I have a duel battery set-up in my van, one purely for cranking the motor, and the other just for the electrics. It appears the cranking battery has decided to pack it in, and fair enough as it is four years old.

This has led me to thinking, how would I go about "jumping" the auxiliary battery to the cranking battery(or direct to the starter) if this happened whilst in the bush?

Can someone help me here?

I believe you can use jumper leads to connect the two batteries together, but is it + to +, or + to -? I know one way gives you 12v and the other 24v, but no sure which is which. Also I believe you can connect the + direct to the starter, and the - to any part of the motor for an earth, is that also true?

All you have to do is use the Aux battery as if it were a second vehicle....

connect + to + and - to - and crank away.......

I always make a habit of connecting the + terminal first.

I have vehicles with dual and triple battery setups here and do it all the time.

to get 24v for emergency welding etc , the batteries must both be out of the vehicle, and connect the + from one battery to the - on the other........ you are then left with 2 terminals left, + on one battery and - on the other.
If you have a welding rod and a pair of jumper leads, you can connect the red lead to the + and the black to the - and then on the other ends of the leads, clamp the - lead on the job with the jumper lead clamp, and put a welding rod in the other jumper lead (red) clip and you have an emergency welder.......... I always carry around a bit of welding glass wrapped up so I can see what I'm doing without weld flash.
Just remember that the batteries will drain fairly quick, so its wise to have a second vehicle to jump start off if you need to......but it is a great way to get out of trouble in the bush or the outback when something busts.....

cheers
Harb

cheers
Harb

i`ve used my secondary battery to jump start my primary battery about 10
times in 25 years.connect your jumper leads positive to positive  and
negative to negative.
   i`ve always had mine set up so that everything runs off the
primary,except my driving lights run off my secondary.the reason i have
the the lights on the secondary is because i feel it would not be good
for a battery to keep bombing a charge into it and never drain any power
out of it.    i always have my newest battery as the secondary battery
and when i turn off the ignition the secondary is completely taken out
of the electrical system.   that way i`m always pretty sure i`m going to
have a good battery to start the troopy
   

G'day Dunnart;

Yes, you can use a set of jumper leads. Make sure,positive goes to positive and negative to negative,that way the batteries will remain in parallel,giving you 12volts and enough amps in cranking power,to jump start your motor,from your auxiliary batt. Pending that your auxiliary batt isn't flat also.

Cheers kon61

G'day Dunnart;

Forgot to mention,get yourself a 12volt rechargeable portapack,which these days are not only going cheap,but also offer more useful built in accessories than just kick starting a flat battery.


Cheers kon61

Thanks to all, great info.

I think I will put one of those 12v rechargeable portapacks in the van as they have all sorts of uses (as kon61 says).

Here are a couple of uses I can think of, some may have other ideas?

* jump-start car.
* charge detector batteries etc....
* portable camp light.
* even a spark to start a camp fire if no matches.

How good these units are I don't know, but in Supercheap, Autopro, Repco etc.. I've seen in thier battery sections a gadget about the size of a cigarette pack that jump starts your car via the cigarette lighter socket.
Apparently from a dead flat battery, you plug it into the lighter socket, let it sit for a few minutes then hit the key.
Recharges via the lighter socket then stow it away in the glovebox or under seat ready for next time.

Do you mean one of these madtuna?


http://www.supercheapauto.com.au/online-store/products/240V-500MA-CHARGER-SUITS-ALL-JUMPSTARTS.aspx?pid=206610#details

no mate, this was about $50.00 and a bit bigger

What about this?

http://www.supercheapauto.com.au/online-store/products/Battery-Fighter-Junior-Battery-Charger-750-mA.aspx?pid=100550#details

[quote="Dunnart"]What about this?

no thats not it, it has a plug that goes into your cig lighter socket

Those rechargable portable batterys are good for a lot of things like starting your vehicle if the main battery just happens to be a bit low.
But they are no good if your main battery drops a cell as they on their own have not got enough power to start a toyota Diesel.

Been proven that it is dangerous to rely entirely on them

Ron

I used to do a lot of spotlighting years ago and learned the hard way not to rely on one battery out in the bush.
I run two batteries with an isolation switch in between. So when i'm driving both batteries are on charge and when i'm running a spotlight or charging detector batteries etc i switch the second one off isolating it.

Brett

Hi hope this is helpful... I recently had a chat with my local autoelectrician after he fit into 12/240volt invertor into my Cruiser. Anyway he mentioned a device called a Smart Solenoid that retails for around $160. When fitted, this Smart Solenoid will allow power to be drawn directly from the aux battery to crank the engine if the primary battery fails for whatever reasons. This sounds like a Great idea to me and at a good price too

There are many excellent brands of battery management systems on the market with varying prices. They take the guesswork out of looking after your expensive batteries. Just do a google search or visit an ARB store or similar 4wd specialty store... or a GOOD auto sparkie.

Robert

Morning Dunnart,
There is a lot of info on the Internet, just type "Dual Battery Setup" into your browser.
My set up I use a solonoid between the main & auxillary. Have the solonoid to activate when the vehicle is running. When stopped if lights are inadvertantly left on only the main battery is flattened. Word of advice using this system, wire the solonoid to both batteries.
Here is one example from the internet.
http://www.4wdsystems.com.au/index.php?id=24

Cheers
Peter