Portable Dual Battery Success!

G'day,
How I have set it up was exactly how it was in my old mans hilux, it's the same system but took it out before I sold it. There is no fuse between the main and the anderson plug. There never was to start with. Should there be?
I definitely wouldn't install the 2 pin plug without an inline fuse.
Between the main and anderson plug is 8mm lead. Then from the other anderson plug is the smaller lead connected to the battery.
When I first wrote the thread I couldn't upload any pics? It said "for paying members only" or something similar. As I wanted to upload a picture.
Misha

Upload your pics to a hosting site such as tinypic first, copy their msg board ink to your pic & put it in your post via the insert images & files button down below the submit button. Clear as mud?

With your dual battery system; I'm no expert, but I'm informed you should run both cables all the way between both batteries in case of the earth shorting out on the chassis & causing catastrophic engine problems via the cooling system.

I Disagree in the strongest terms that all connections should be soldered.
It is proven that properly made crimp connections are more reliable than soldered connections.

I do agree that the cabling should be well mechanically protected and all pentrations should have gromets or such to prevent chaffing

For anything other than cranking or winching circuits there should be fuses or circuit breakers, as close to the batteries as possible.


As for running the negative all the way back to the battery.....yes preferable, but there are many wives tales about not doing this.

If you are earthing to the chassis, make sure the paint was scraped away under the earthing bolts, preferably add some never seeze or at lest grease to the threads, bolt heads and washers and use two nuts ot a locking nut.

Don't forget to secure that battery well, and to provide some ventilation even if it is a so called sealed battery...there is no such thing as a completly sealed battery.

cheers

Hey guys,
I did both. I crimped a couple as well as soldered. Nothing a vice isn't capable of.
I'm assuming you guys are talking about a maxi fuse? These were never used before so do I need them? It worked fine before without them.
Yes the paint was scraped away, but to test it I just touched the negative wire with positive if you get sparks it that means current is passing well.
I did hear about ventilation, it's not a sealed battery , but it's not in the car all the time so should be fine.
Link to the pics
http://tinypic.com/r/2cg0yv5/8
Misha

http://tinypic.com/r/fc4tqf/8

if that is not a sealed battery you need to be well aware that it will release significant amounts of explosive gasses and acid mist while being charged.

you need to be damn sure you have plenty of ventilation.....better still get a sealed battery.

secondly, remember what you have there is a 15 to 20 KG plastic box full of lead and acid....if that gets free in an accident or rollover it could do some real damage.

seriouilsy it needs to tied down well and you need a selaed battery.

cheers

The wives tale I heard came from a retired TAFE lecturer who had also worked as a trainer for the RAA; apparently, according to him, earth leakage can react with engine coolant to completely wreck the internals of the vehicle cooling system. But hey, what would he know lol!

Yeh there are some very interesting leaps of logic arround.

The biggest issue with grounding to the chasis is the adequacy of the return circuit.
many cars have a chassis bonding strap from the negative battery that is simply not up to the demands of a second battery.

If you are going to ground to the chassis, best to check the size of the bonding strap from the battery negative to the chassis.....hell...just upgrade it anyway....I have seen a few fail without a second battery.

then realise that some parts of the chassis or body may not be properly grounded if at all.

Most ute trays for example are not properly grounded to the chassis.

this is whay it is best to home run you negative all the way back to the battery.

cheers

Hi John and Regina,

The cable to the auxiliary is actually 6B&S not 6mm. My bad.

I have looked into this for some months now, and some people said, you can't have a battery in the car due to a gas, bit in speaking to the guy at the battery shop all should be fine. His exact words were 'if your not sleeping in the car, and as long as that battery isn't smothered, you should be fine. They emit the smallest amount.' He also said it isn't illegal to have them in you car, so with these questions answered, away I went!

That's a new one KevinE. Haven't heard that one before!
The trick is, how do you find out if the battery is actually charging? Obviously the isolator LED lights up but.. Now sure.
http://tinypic.com/view.php?pic=317eag2&s=8


Misha

Maaate..if its a screw top wet cell battery......not sealed..they emit quite a bit of gas.

seriuolsy.

cheers

..So do I..:)

VW Beetle I had 30 years ago had battery under the back seat. All good. Only caught fire once when springs under the seat shorted on battery due to a little bit of "off road" driving + passenger bouncing.

So probably best to avoid one in the confines of the car if you can but probability of an issue pretty low under normal conditions.

Cheers
Greg