Dual Battery system

[gfm_69]

Hello all,
I am having a hell of a time finding out about dual battery sytems. Both ARB & TJM are telling me there underbonet trays only fitt 8 inch batterys but I am looking at 10 inch for a good battery.
Under the bonet is the only option for me.
I have seem what buzzys and tritinasaurus have made but I have no welding skills what so ever and was wondering if anyone had plans so I could get some one else to make for me. Cost is not a real concern with in reason of couse. Does anyone have a TJM or ARB tray fitted with a 8inch battery and could tell me how well it work with the fridge would also be great.
Cheers

GFM-69

[Buzzy]

gfm,
I got your PM just havent measured the battery yet but mine is a 8inch.
There is not alot of room to fit a 10inch batt there as mine already sits very close to the firewall and the other end of the main batt is touching the power steering resivor hose.
There is also a AC line that runs very close to the front of the main batt.

[Buzzy]

Ah yeh you dont have to be a good welder to do this either as its only inch angle, not much to weld.
Slap some birdsh!t in there and you wont have a prob thats the boilermaker coming out in me

[sam]

I have fitted a 9" second battery in no probs, which is a 70 or 75 amp/hr but I think that
is about the limit but still pretty good imho

[gfm_69]

Sam, have you fitted a TJM or ARB tray or is this something else?

[Blue]

Can I ask why under the bonnet is the only option...??? A tub mounted battery can still be wired back into the cab with relative ease...

[gfm_69]

Blue, I just want to be able to use the tub for any object,shape or size, thats all.
I dont want a battery box to affect this as the tub is small enough already when it can be fitted under the bonet.

[sam]

Neither I made my own from some zinc plate I got bent at 90* approx 50mm x 15mm then cut and welded
the corners at 45* .
I then made a support bracket that attaches onto the firewall and one where the battery cables used to along
side the base .
Was also necessary to cut some excess length off the power steer hose to clear the orig battery when I moved
it forward.
As said before did some very rough/corrugated roads on our last trip with no probs at all

[Nick 08]

I have fitted a second pirhana battery tray from TJM for $150 i put a sealed gel oddyssey Battery which is only 6" square.
then i used that as my main battery and got a sealed 100 amp/hr battery which is smaller then the factory piece of crap and have heaps of room left in front so
i was thinking of putting a fuse box in the unused space at the front.

[nev08]

Ive fitted a ABR sidewinder box in tub, They have anderson plugs for quick removal. Fits 130ah + battery> Happy so far, very quick to intall comes prewired with charge mangement, fuses etc.

[barraxt]

We used to run a Waeco CFC45 for 4 days and the 8" (55AH) auxillary never cut out with the fridge on 11 Volt safety.

[Blue]

Blue, I just want to be able to use the tub for any object,shape or size, thats all.
I dont want a battery box to affect this as the tub is small enough already when it can be fitted under the bonet.

That's fair enough gfm, mine is in the tub, removable as I found that I'm rarely in need of the battery when I need to utilise the full expanse of the tub - 2 anderson plugs and I'm back charging and have power to the aux outlets... The battery spends most of it's life on a battery maintainer on my work bench...

[andyj]

I have the TJM tray and an 8" battery no probs running the 50ltr Waeco on the trip last year put the 2nd battery through a redarc controller just fitted a piranha DB 180 (which i got from the site) to run the battery in the trailer on anderson plugs no problems

Andyj

[shaunv8]

Hi Guys,

I have an MK triton and would like to install a 2nd battery for lights and engel when camping. I see some of you have a setup which is removable when not camping. Could anyone please elaborate on HOW this is done, whats required etc etc etc.....

Thanks Shaun

[subi_man]

shaunv8, I carry my 2nd battery in a box in the tub. It has a power outlet for the fridge on top, and Anderson plugs for the charging wires. Hope that helps

[craigs]

To those that are considering dual battery systems- I was in our local repco yesterday and they had two dual battery kits for sale at $145, Managers special, probably a stock clearance item. A quick look inside revealed that they included a fair amount of cabling for an under bonnet setup, Matson dual battery module and battery terminal fittings. Worth considering I thought.

[Naff]

** Moved from another thread **

What is the best sort of battery to have as the second battery in a dual setup?

I originally thought I'd need a deep cycle battery to keep in the back and run my compressor and cheap a$$ fridge etc., I'm not so sure anymore. Obviously the deep cycles are more expensive and last longer etc, but I doubt I will make full use of it until such time that I load it up with a decent fridge (which is a long way off).

So I'm now of the thinking that an everyday heavy duty battery might suit my needs.

Appreciate some thoughts on this!

[boycee]

Mr t has mounted his battery on the towbar in a box and that is out of the way. No welding needed just some thick steel plate and some bolts. He has a 300 ah battery there.
Just noticed you have the arb rear bar though so maybe have a look and see what you think.

[King Triton]

NaffX214

The whole idea of a second battery is to give you more A/H (amp hours) because you do not have enough capacity in your main battery.

The mian difference between a cranking (normal) battery and a deep cycle battery is the way they like power being drawn from them. A cranking battery loves large burst of current drawn quickly where as a deep cycle battery likes small constant current over a period of time being drawn from it.

The common consenses for cost versus A/H versus durability versus maintanence is that AGM (Absrobed Glass Mat)batteries are the go. They are sealed and can be mouted in any position.

You need to work out how many A/H you will be using and for how long to determine what size battery to get.
to do this look at the equipment you want to run and check out the watts rating.

to calculate amps drawn per hour divide watts by volts

A 12watt 12v fluro will draw 1 amp per hour
12watts divided by 12 volts = 1

Where as a 50watt 12v light will draw 5 amps per hour to run
50watts divided by 12 volts = 5

Then you need to work out how long you want to run these items for and you will get an total amount of A/H needed. There are other factors to try and calculate like if you will be driving everyday as this will charge the battery. There is a whole science to working out what you need including solar panels etc. but i think the best is to buy the largest capacity battery you can afford and fits where you want it. you can never have too many A/H

A good quality deep cycle battery can be drained down to 80% of its capacity where as a cheaper one can only be drained to 60% of its capacity.

so from a quality 100 A/H battery you can use 80 A/H
good quality Full River AGM 110A/H batteries can be bought on ebay for $350 delivered.

If want any more info let me know.

[Naff]

Thanks for the info King..

All I am running off the battery for now is a compressor (on board air) setup which will only get used from time to time when I am off-roading (maybe once a month at this rate).

Then I have a couple of accessory sockets - I'll probably plug my very cheap esky sized fridge into it if I go away but I mean it is very cheap. Then I'll probably use them for little air pumps or work lights etc. when campign (again, rarely).

So at this stage I'm not using it for a lot, but just setting myself up more for the future.

I use the car daily.. so it would always be charging.

[King Triton]

Like i said i would get the biggest A/H battery i could afford as you will always find things you want to use when you do start to go camping more often.
are you mounting it under the bonnet or in the tub?
The only thing with cheap fridges is they use alot of A/H's compared to a waeco or engel which average 1 amp an hour.

[greeny03]

Would have to agree with KT on battery size!! Also, even though youdrive everyday, the battery will never be charged 100% even if its not in use. This can only be achieved with a battery charger, or topped up with solar panels and a regulator. The alternator won't put the charge back in properly. I own a Ctek charger which has a recondition feature built in. When purchasing my battery it was recommended that it has a regular seperate charge to maintain a healthy battery for a few if not many years.

[Naff]

In a purpose built toolbox in the tub King... also maybe inside a battery box like subi posted earlier in this thread.

Thanks for the info again guys.

That issue on never charging fully - wouldn't that apply to the primary battery also?

[greeny03]

Yep!! More so with AGM batteries, but if any battery is put on a good charger it will 100% charge the battery.

[Naff]

So I picked up a 105Ah battery with a 700Amp crank capacity... a Supercharge Allrounder. Pricey, but reviews seemed ok.

Now.. the little Smart Start Redarc I purchased 'recommends' the used of a 100A fuse between it and both battery's positive terminal. Now.. I like to think I know a bit about electrics, but can't fathom why this fuse would be necessary. The Redarc is essentially a 100amp solenoid with a bit of smarts in it. What are those fuses going to protect? It's probably something quite simple that I've overlooked...

If it was mandatory, I'd probably do it, but it is only a recommendation??