View Full Version : GQ dual fuel and second battery

25th May 2012, 10:09 PM

I've a '95 GQ 4.2l on dual fuel. I'd like a second battery which is reasonably sized. My can-fix-it-mechanic tells me he can easily move the parts out of the way within one hour. Problem is I need a decently sized battery cradle (I think 12"). All I found so far (Piranha, ARB) for the petrol version of the GQ is a cradle for a 8" battery which would give me some 55 Amp hours. My more-upmarket-mechanic tells me that install would set me back 1400$ and I'd be better of with a battery pack with similar Amp hours for 750$ installed. But I'd like the second battery not just for the fridge but also as a backup and for emergency welding should I break something in the middle of nowhere. That's why I hesitate to go with the battery pack.

Does anybody know of a good quality battery cradle for a ~12" battery to mount in the engine bay?

I'd also consider a battery between my storage system and the cargo barrier but then it has to be a fully sealed one which according to my more-upmarket-mechanic would get expansive again. Any experience?


25th May 2012, 10:26 PM
battery world can order in trays also try them, maybe look at getting the batt tray size you want from a wreckers and modifying it to suit you rig or alternatively stick a agm or a gel battery in the boot you can probably pick one up for $340 for a 130ah.
whats the $1400 going to cover moving parts, fitting/fabricating a 12" tray and installing dual batt setup ?

26th May 2012, 12:02 AM
Thank you for the advice. I'll give them a call.
The 1400$ is for a full install either of a 8" battery in the engine bay or of a gel battery in the boot.

26th May 2012, 12:23 AM
Thank you for the advice. I'll give them a call.
The 1400$ is for a full install either of a 8" battery in the engine bay or of a gel battery in the boot.

Wow, he sounds very up market

Taps a lot!!!!!!

26th May 2012, 12:43 AM
What dual batt system is he using? it is sounding like a bit much for my liking but i fitted mine myself it is seriously very easy and a good to know how it is installed in case you have an issue out bush to make reapers

if you cant fit it also ask batt world about fitting also as they do that too

26th May 2012, 03:33 PM
I'm not sure what they use. It's all only good quality as far as I can see.

I do think about fitting it myself due to the two reasons you stated: money and knowledge. Still would prefer the 2nd battery to be in the engine bay. Battery World don't have them for the GQ. :(

my third 256
27th May 2012, 08:04 AM
when i did this in my 95 ti petrol gas 4.2 about 3 years ago
all parts came to $550
try this mob they were great for the tray but i got one from arb a lot cheeper than theirs
tray $130
battery agm $140 from a battery store ask if they have any scratched ones or lable dammager or fallen off much cheeper
red ark battery managment $100
cables and battery cable ends its big stuf dont go small,battery terminals ,rear socket and cable to this go 12mill then no power loss well very minimal $180
hope this helps also you can link the batteries together to achive a higher amp hour without going the largersize tray and battery with the redark manager

27th May 2012, 11:04 AM
i think you missing something what mob?

27th May 2012, 05:21 PM
Hi there, my first post. I fitted a 2nd battery to my 12V 1996 SWB patrol so I could have a second start battery and an isolated battery for my winch and accessories. They are linked through a 350A switch (#4721) which isolates the main start battery. Should this battery get flat, I switch over to the spare. I used a VSR (voltage sensitive relay) module(#3099) to charge the second battery. It's been working very well. I fitted a large second hand deep cycle battery cost, box of beers. I made the battery box to fit (same size as the start bat. box) Total cost of job, (VSR= $129. Switch $70) a couple of hours work and about NZ$250. Also used the battery link cable out of a 24V safari to link my batteries. I may have to buy a new battery one day though.

28th May 2012, 12:24 PM
Thanks for all your replies.

I came across a tray from Piranha for the 2.8l diesel which sits passenger side at the firewall and is 12". With moving a few parts out of the way this should fit. Price for the tray is around 180$ (same as at that ebay dealer from "my third").

28th May 2012, 02:41 PM
what dual batt set up are you looking at i highly recomend a "ctek d250s dual" mines been working a treat its a dc-dc 5 stage charger and puts out 20 amp after haveing a typical isolator dual batt set up kill 2 of my batteries ill never get a simple system like that again. you can use it as a solar regulator also. this one cost me like $260 redarc have one also that puts out 40 amp but i didnt have $400 to spend on it

28th May 2012, 08:10 PM
I didn't do all my research yet but I'm aiming for a charger, not a basic isolator. It just sounds like one gets more out of the expansive setup with the right hardware in the middle. I did look at the ones from redarc so far but will try to find out more about the ctek version. Thanks for the recommendation. As far as I've seen redarc also has the chargers with other amp outputs, not just 40 amp.

This might be a stupid question but do I need to run two cables back into the boot of the car (fridge, lights and 240V) or is a connection to the car body good enough?

28th May 2012, 08:22 PM
you will be able to find a good earth in the back without any issues no problems there. you may want to run one large positive to a fuse box it will make it so much easier for future modifications just make sure you fuse it at the battery and the fuse has to be large enough for all the accessories you have running off it .

i just use these ones and solder all one side together with the gauge of wire used from the aux batt. http://www.supercheapauto.com.au/online-store/products/SCA-Automotive-Fuse-Box-8-Way-Blade.aspx?pid=120460&menuFrom=5014#Description

just make sure its all insulated good to prevent shorting out on whatever you mount it on
or baintec make some good better units but you pay for it.

25th June 2012, 10:36 PM
Little update: The Piranha BTGQ2.8 is installed in my 4.2l petrol/lpg GQ. It suits a 12" battery and sits on the co-driver side next to the firewall facing forward. It's not a quick / easy install: my mechanic took some 2.5 hours to relocate all the bits and pieces. LPG and snorkel didn't help neither... But it's an option which I prefer over the standard ARB or Piranha choices which only suit 8" batteries.

Now the fun part of installing the electrics can begin. I'll go for the "ctek d250s dual" megatexture recommended (20 amp output). Any suggestions for batteries?
How big (amp) of a circuit breaker do I need?
I think I'll opt for a Baintech fuse box.
Any recommendations on where to by cabling, bits and pieces?

25th June 2012, 11:33 PM
wow i should start makin battery trays, $180 therez not alot to them, cld easily fab some up haha

hooked in on tapatalk

26th June 2012, 12:35 AM
yea I’ve seen my mates LPG dual fuel set up and it makes a mess of the engine bay and it’s not really stuff you want to play with if you don’t know what you’re doing but glad you sorted it out for a larger batt a 8" wouldn’t have been worth the effort .
I’ve got 100 amp fuses on each battery and you can pick up wire from any auto shop and bigger is better. if you don’t have the crimps for the wire lugs you can measure the exact length and get the auto place or your mechanic to crimp them on for you more than likely for a fee but you want them on good .

edit: 100amp fuses as i have 100amp wire being used

2nd July 2012, 09:37 AM
Thanks for that. I just keep asking if that's ok. ;)

I'm a bit confused with wire sizes: there seems to be diameter in mm and cross section in mm2. It's not always clear to me when people talk about which one.
Would something like this be overkill for example? http://www.jaycar.com.au/productView.asp?ID=WH3070&form=CAT2&SUBCATID=995#1
Or is this closer to requirements (including the 100amp you mentioned)? http://www.jaycar.com.au/productView.asp?ID=WH3064&form=CAT2&SUBCATID=995#1
I would go for a circuit breaker like this: http://www.jaycar.com.au/productView.asp?ID=SF2266

2nd July 2012, 09:02 PM
bigger is better but over 2m length you will have under the hood voltage drop will be minimal if it were to a trailer out the back on an Anderson plug the larger would be great but may be overkill its up to you. watch the placement of that circuit breaker it looks like it may clog up with a bit of mud and the last thing you want is for it not to be able to trip during a short.

3rd July 2012, 09:54 PM
That's great advice on the circuit breaker. I had missed that detail.

3rd July 2012, 10:45 PM
I thought you brought a battery factory for $1400 seems pretty high IMO, add up the amps of what you think you'll use up size from there, marine style battery handle the bumps a bit better, they wouldn't sell me a sealed battery for under the bonnet saying it might explode but this just covers them OHS issues my aux is a 105 AH trojan with a wet kit.

4th July 2012, 09:50 PM
I didn't go for the $1400 option. Even the mechanic suggested not to because of the small battery he could fit in (8"). Instead he suggested a Engel battery pack with 55AH. Now, with some help of another mechanic, I can fit a 12" battery using the Piranha tray for the 2.8l diesel.

Interesting with the sealed battery. I thought the gel ones would be ideal for 4WDing.

4th July 2012, 10:02 PM
the heat under the bonnet can dry out the gel prematurely killing the battery and also agm’s aren’t recommended either though you will get conflicting information on if they can be used under the bonnet depending on the supplier/ manufacturer probibibly best bets a led acid or calcium maintenance free battery looked after will give a good service life and won’t cost the earth

5th July 2012, 09:21 AM
Thanks to both of you.
I would have gone for something like an Optima since it's advertised on Ctek's website together with the dual battery systems.
More complicated than I thought...