Duel Battery setup - Dirt Cheap - ..Help me out!

[driftdave]

Thanks everyone for your input!
Struth - pretty sure that won't run my fridge!
Clarky - nice unit..blow my budget out of the water unfortunately.
What is the benefit of a dc-dc charger over an in car type like what Squire is recommending?
Supercheap has a much cheaper dc-dc ( I imagine it is not redraw quality...but the price!)
http://www.supercheapauto.com.au/onl...ecommendations
Squire - very impressed with the home12volt stuff.

[driftdave]

At present i am thinking:
this -
http://www.home12volt.com.au/extreme...0-package.html
&
http://www.home12volt.com.au/blue-ap...hicle-kit.html
which pus me at $400 shipped

OR

http://www.home12volt.com.au/thumper-60-ah.html
$500
Yeah it is smaller and less capacity, but a little more portable and can jump start the WH.

Thoughts?

Cheers
Dave

[Squirejames359]

Originally Posted by driftdave

At present i am thinking:
this -
http://www.home12volt.com.au/extreme...0-package.html
&
http://www.home12volt.com.au/blue-ap...hicle-kit.html
which pus me at $400 shipped

OR

http://www.home12volt.com.au/thumper-60-ah.html
$500
Yeah it is smaller and less capacity, but a little more portable and can jump start the WH.

Thoughts?

Cheers
Dave

If I could stretch a $400 budget to $500 I would definitely get the 60Ah Thumper: it comes with the 50Amp charging kit and jumper leads. Also, when the batteries wear out you can just get it re-packed with the little 15Ah redbacks; same as I put in my home-made battery box. In fact, the reason I chose those batteries over any other cheaper ones was because I knew they were the batteries used in Thumpers. I know plenty of people with the Thumpers, no bad stories, they're an awesome, well built piece of kit. If I could afford one, I'd have one.

My 2 cents,

[driftdave]

Cheers Squire,

They do look like a well engineered piece of kit.
In reality I wanted to get out of the whole job for ~$350.
So I am really struggling to jump to $500.
I do realise that this is a Christmas sale for the older model, but it would do me.

Would the charger you recommended, charge the 100aH battery in the battery box?
How does that work? As the fridge will be connected constantly, i am draining the battery whist charging it?

[Hayesio]

You just need a cheap battery box or tray and some way of securing it in the rear (if that's where you want it). Then you need a dual battery isolator (volt sensitive relay) capable of handling the starter current (probably around 400amp for 5 secs). You then need to run heavy gauge cable between the starter battery and the aux battery with the dual bat isolator in the circuit on the bonnet side. The cable needs to handle the starting current, so probably 50mm2. Mine is 70mm2 (diesel). This sizr cable will also give you excellent charge voltage. From the dual batt isolator you need to run a bypass switch into the cabin. This switch will apply an earth signal to the dual bat isolator bypass terminal. You can't fuse the line because they don't make fuses/CB for 400amp, so the cable needs to be very well protected and of SAE grade. I would recommend a AGM battery of the largest capacity you can afford, capable of 4 or 5 hundred CCA.

Charging a dead 110Ah battery at anything less than 80 to 100 amps will just be a pain in the backside...

[anthonygubbin]

There is another Dc-DC step up charger on Ebay. Its a quality unit and is under $200 from memory. For the life of me I can't remember the brand. but look up this seller autoelecau he was the cheapest 18 months ago. Some 8bs cable and two circuit breakers and you will be set. Circuit breakers are the best for protecting the cable as there is zero loss. Keep in mind the charger I am referring to is only 10a but the fridge should overall draw 3-4amp.

Regards A

[anthonygubbin]

Originally Posted by Hayesio

You just need a cheap battery box or tray and some way of securing it in the rear (if that's where you want it). Then you need a dual battery isolator (volt sensitive relay) capable of handling the starter current (probably around 400amp for 5 secs). You then need to run heavy gauge cable between the starter battery and the aux battery with the dual bat isolator in the circuit on the bonnet side. The cable needs to handle the starting current, so probably 50mm2. Mine is 70mm2 (diesel). This sizr cable will also give you excellent charge voltage. From the dual batt isolator you need to run a bypass switch into the cabin. This switch will apply an earth signal to the dual bat isolator bypass terminal. You can't fuse the line because they don't make fuses/CB for 400amp, so the cable needs to be very well protected and of SAE grade. I would recommend a AGM battery of the largest capacity you can afford, capable of 4 or 5 hundred CCA.

Charging a dead 110Ah battery at anything less than 80 to 100 amps will just be a pain in the backside...

Why does the OP need to run cranking power through the isolator? Seems a wasted exercise to me if the battery is going in the boot. To do this he needs 200amp cable right through. IMO pretty hard to make a neat job with big fat cable going all the way... If the OP wants to run a fridge why would he need to jump start his vehicle?? An isolator is there to protect the crank battery anyway... Apologies bloke but I'm a little confused with your method.