Dual Battery set up

[Miyagi]

Hey all,

i'll be putting in a second battery in my NH this weekend and was after some hints, tips, pics ect ect.

oh and while i'm at it i'll be doing the head gaskits as well

cheers

[-Scott-]

Without knowing the bits you're using it's a little difficult to be specific. A couple of tips which may be relevant...

• Relocate your carbon canister to the bull bar so you can stick the second battery near the first (you probably planned this anyway. ) If you have ABS (do you?) you can't stick it on the driver's side, and if you don't have ABS that space is perfect for an underbonnet compressor. That's what I think, anyway.
  Have some "quick disconnect" ability on the second battery. (I use a fuse, but if you're winching that may not be good.) I've found mechanics only ever disconnect the primary battery. With my isolator (Jaycar unit using FETs for the switching) if they disconnect the +ve from the main battery and let it hit ground there's a brief flash, and I have an hour or two of work ahead of me.

Good luck,

Scott

[Miyagi]

well at this stage all i've got is the battery, thats why i'm looking for info. found the thread in the FAQ section. i'm just after some pics of how others have fit the second battery in the engine bay.

[Bitsamissin]

This is what I did : -
- ARB dual battery solenoid which gives preference to charging starting battery then 2nd battery if starting battery is low for some reason it will draw current from 2nd battery to help crank the motor
- second battery (deep cycle) is where the carbon canister usually resides (Piranha battery tray)
- carbon cannister welded to the side of factory battery tray
- winch is wired to starting battery
- rear accessory socket with 30A fuse and wiring wired to second battery along with UHF radio, GPS & twin rear compressors
- Piranha dual battery monitor on dash
- front ciggy lighter & accessory socket have the fusible links removed but are still wired as factory (to starting battery)

Works very well and I can get about 3-4 days out of the Engel before needing to charge.
I'll be replacing both batteries (4x4 Exides) with Optima yellow tops soon as the Exides are getting on a bit.

[99Montero]

Are there any dual set-ups for a petrolium Pajero/Montero. I have looked under the hood and have not found the space available to do something like this. Any ideas and/or pics?

Thanks,
Angelo

[-Scott-]

Angelo

Have you browsed through the Pajero Club Forum? There's a number of members there with two batteries, and I'm fairly certain there's a few pics too.

I believe ARB make a battery tray to hold two batteries, which replaces the existing tray.
I think fitting requires movement of aircon pipes, but it doesn't sound like a huge job - I guess fittings need to be loosened, which may lead to loss of gas, so it might be a job for an auto-air specialist.
Of course, your steering column/brakes(/clutch?) may get in the way...

Battery box in the back?

Scott

[4runna]

How do you find the pirhana battery monitor frank? is it able to be fitted to any setup? I have never really bothered with anything like that except an ammeter on the 2nd battery connected up on the drawers in the back of the truck. prolly will change it to a voltmeter though as the corrugations on the last trip killed it :(

Mine is just a pirhana battery tray on the firewall. I use a redarc solenoid. I initially was using a sealed deepcycle battery (that could also handle high charge rates) but found that it was causing over charging of the main battery, so recently replaced them both with almost matching cranking batteries that have a standby rate of 120AH, so shouldn't run them down too low to damage it even with the fridge and invertor etc.

I did a similar thing to frank, wired up cbs and radio +all aux sockets to the 2nd battery so i can leave them on.

Rob

[DougH]

Angelo

Of course, your steering column/brakes(/clutch?) may get in the way...

The master cylinder gets in the way on our driver side, your passenger side. On the other side of the compartment there is the ABS module. Honestly I would love to take the ABS out and replace it with a regular master cylinder.

[-Scott-]

Angelo

Of course, your steering column/brakes(/clutch?) may get in the way...

The master cylinder gets in the way on our driver side, your passenger side. On the other side of the compartment there is the ABS module. Honestly I would love to take the ABS out and replace it with a regular master cylinder.

Bugger.

I presume the ABS module has electrical and hydraulic connections - what would be involved in relocating it?

Scott

[DougH]

Actually I would want to remove it.

You might need a new master cylinder, and you would need to to pipe all of the hard lines. I have some lines starting to look crusty so I guess when ever I replace them I am going to look into it.

[grumpy221]

have a look here
http://www.pajeroclub.com.au/forum/foru ... PN=0&TPN=2

[grumpy221]

oh and make sure the new tray is very secure mine has come loose from the fire wall and dropped on to the aircon pipes going into the cabin created a leak......

[mark0069]

my duel batt system
dual battery isolator + battery monitor from abr
battery tray from superceap autos
terminals and battery cables from peps

i removed the antipolution canister bracket then pushed the canister down ner ac pipes fitted bracket from motor to batt tray put rubber pipe over ac pipe sat batt tray on top of pipe and bolt through inerguard.

then used the canester bracket holes to mount isolator.

ps battery is very secure

[0xyg3n]

Here is a pic of the duel setup I had in my old Paj. Basicly extended the orig battery tray in length and added some "legs" to secure and suport it.

[Alej Altuve]

Can I run a two batteries setup without the swich or insolator???I'm thinking of puting positive with positive and the same with a negative.....

What do you think????? it is posible????

[-Scott-]

Certainly possible, but you have no "safeguard" against a flat battery. They'll both go flat together; it will only take a little longer.

It all depends on why you want the second battery.

Cheers,

Scott

[DougH]

You can but they should be identical batteries purchased at the same time.

[Miyagi]

You can but they should be identical batteries purchased at the same time.

Why's that?

[fool_injected]

If one battery is lackin condition the other in good condition will try to 'charge' it.

[Miyagi]

If one battery is lackin condition the other in good condition will try to 'charge' it.

and?

(sorry to be ignorant but i've had little experence dealing with this sort of thing)

[fool_injected]

Say your battery 1 is brand new ie holds a good charge
Now say your battery 2 has seen better days, is lesser in quality or lesser speced

A good battery will hold 13.6v but as they wear they can hold less
What happens is the battery2 drains from the good battery1 even without a load. They try to equalise

Effectively you only get the performance of the lesser

Worse still if one battery fails it will kill the outer

[-Scott-]

Just to be contrary, I don't believe that this is an issue. Once both batteries are fully charged they will deliver whatever current they can given their terminal voltage. If one is in better condition than the other, it will deliver more current, but their terminal voltages will be the same - because they're connected.

If they're being "float charged" with the correct constant voltage, they'll each accept only the current they want, until they're fully charged - and one will almost be fully charged before the other.

If one battery is flat, the other won't be able to charge it - because a fully charged battery hasn't got the terminal voltage which is required to reverse the normal discharge reaction, and charge the dud battery. (Anybody who actually pays attention to anything I write may recall that I've previously said different in other threads. I now think I was wrong. )

Notwithstanding the above, I do believe it's a good idea to do as Doug suggested - if you're going to permanently wire the two batteries in parallel. I don't believe it's as critical if you're using a "smart solenoid" which preferentially charges your starting battery.

Note that none of the above applies to two batteries in series i.e. 24V operation. It's absolutely critical that the two batteries are identical, and identically charged when they're initially connected.

Cheers,

Scott

[Miyagi]

oh.

i get it

thanks heaps, lot of info here. I think gonna run it parallel for the mean time, if it causes problems than i'll look into a different set up. just gotta finish the heads and fit it in.

cheers