Hi guys and gals

Not sure where to post this as it’s a tech and audio install for a second gen...Get my issue.

This is a guide to install a stealth second battery and sub woofer into a stereo system for second gen wagons allowing you to keep all your room including the cargo barrier if fitted.

This setup required me to delete the spare wheel as i require the space in my wagon for work.
I have a bottle of tire weld and a compressor instead. For long trips i plan on getting a space saver and mounting it to the side of the wagon or just throwing it in somehow. As there very thin i might just make up a bolt in the floor as a side mount will take up too much room defeating the purpose off this in the first place.

Difficulty is easy to medium for a handy person but time consuming.
That said If you have no idea about pos or neg wires and trim removal it will be hard. But guides are available in the forums for most bits i don’t cover. Feel free to search.
PS Most installers are worse than us so have a go!

System Overview and reason

Any how i have placed a second 90 amp hour battery in the wheel well of my wagon to power my stereo and amps as i like to listen to them with the car not running eg parties or maintenance..

The rear battery is connected to the main battery with a red arch voltage device in-between which allows the battery to charge but will stop the front battery being drained.

My system is split into two running modes. High power all speakers and low power no amps.

I have a rocker switch in the centre console for amps On/Off

Low Power Mode (only head unit and attached speakers.) ACC needs to be on.

Stereo Spec’s to date:
H/D pioneer Blue tooth 3 RCA out, high power.

Amps: Kenwood mono and Kenwood 4 channel, one under each front seat.

Kicker, 1 fared capacitor for Sub Amp

Head Unit powered speakers
Front Dash: 4 Inch Kenwood 3-way (factory location)
Rear Side mount wagon speakers: 6x9 Clarion

Amped Speakers
Front Doors: 6.5 inch pioneer splits (Verada door card upgrade)
Rear wagon floor: 12 inch Rockford punch sub
Rear amped full range speakers to come!

Second Battery install consists off the following parts.

90 amp hour dry cell battery, it is completely sealed and can be used without ventilation in car.
(note: do not use a standard battery inside your vehicle its illegal and dangerous)
2x 100 amp fuse blocks with reset switch and on/off In rear.
1x40 amp inline fuse in front
Appropriate gauge wire from front of vehicle to rear battery
Appropriate wire from rear battery to Amps
Red arch battery isolation device
Ring terminals to suit (Find them from a truck or marine auto elec.)
Rear battery terminals

Tools Required
Wire cutters / strippers
Hammer
Stanley Knife
Circular saw / jigsaw Optional
Mitre saw optional etc
Screw drivers
Drill and appropriate size bits
Angle Grinder Optional

Ok so basically the wire is run down the middle of the car to the rear and from the rear the amp wire follows this route up to the back of the front seats then goes to the amps.
To allow for the cable over the rear hump in the back cut the standard floor ply and remove the gunk off floor leaving a channel for the high current wires. See Photos.
Note: Please don’t run any cables under vehicle as you may cause serious damage to components or the vehicle by shorts and fire. It won’t last anyway!

See diagram and pics, the speedo cable hole is a good place to run the power cable.

The battery needs a tray of some sort to be made up to secure it firmly in place.
I used angle and flat aluminum pieces from mitre 10 as its easy to work with and doesn’t spark when cut, it also can be cut with my mitre saw on a standard blade!!!
The tray is then bolted through the floor with nuts and bolts to secure. To locate the battery i used two adjustable straps from mitre 10, this is very secure and would only be slightly concerned in a severe roll over.
The two fuses are screwed and glued to the wheel tub
The head unit has a separate fuse installed and splices into the main second battery power run. I then used a relay so it only works with the ACC on.
A great thing with my head unit is it has a voltage display so helps keep an eye on things.

Rear Sub Install

One sub! 12 inches, i doubt a 15 inch will fit with this setup. But it is possible with mods before starting.
12 mill particle board 2400x1200 sheet
Carpet to trim (i used the factory wagon mat and a spare one the same colour to save money until i get around to new carpet.)
Screws of varying sizes
Angle aluminium
Carpet glue
(Make sure you have terminal covers for the rear battery as the aluminium comes very close to the battery and may short out)

Template Design

Use the two ply inserts in the wagon and the spare tire cover. Measure the distance between the factory ply pieces at the rear of wagon then place on MDF or particle board allowing for the gap with wheel cover until happy then mark with a pencil. Cut out and trial fit.
You will have to remove the rear most centre latch.
If you only want a sub hole, mark and cut location. I will supply measurements approx for this in my photos. If you are installing a Second Battery go ahead and mark, cut location. Again measurements for a 90 amp battery will be in photos.


Links
Battery Isolator can be bought of eBay around $100

My dry cell battery was purchased off eBay from a Sydney battery store for about $280.00
Cables and fuses from Auto barn
http://www.autobarn.com.au
Cable ring ends of correct size only available from marine and vehicle auto elecs
I used the crush fit type and hammered them shut...work fine and they don’t pull out.

[U]Still going!!!!!!!!!!!!!!! will update soon

Reserved for update and measurements.

This is quite a handy guide, im really interested in doing this myself but just for camping, could you quickly explain how easy it would be to run just a battery with the isolator for only running camping stuff?
Quick diagram:

Car Battery--------Isolator--------Second Battery----camping gear.
And the alternator would charge the second battery?


Would it be easy as running wires from the primary battery with the isolator inline to the secondary battery, and then just running a 12v outlet off the second battery to the camping gear?

Also can you buy wire purpose built for running the power wire from battery to battery, or did you custom make one? If so, what gauge is it.
How is it the power wire connected to the primary battery?

For what you intend yes just run the wire front to back off wagon. Easy!

I have a twin 12volt plug int he back to take power from, Just cigi lighter plugs.

The isolator if mounted on the fire wall just above the speedo cable.

To make the iso connect the two batterys together permanent incase i leave the lights on i have a switch mounted on the dash hooked up to the iso overide. Diagrams are avalible from the above web link.

Just work out if you want a battery box or install like mine.

EDIT
yes this will charge fine.

The wire i used is audio cable.not sure off guage. Used a new terminal on main battery to hold positive run then audio fuse 40 amp inline then ISO then through the car to rear, fuse then to pos on second battery .must fuse both ends.

Diagram here. http://www.redarc.com.au/pdfs/Specs/Smart%20Start%20Instruction%20Sheet-A5-2.pdf

O yeah the diagrams on the website make alot of sense, thats a pretty good product.
Just to make it clear, if i run the wires down the sparewheel well with the isolator wired inline with it and DONT have a battery down there it won't affect the running of the car?
Reason being if i do this setup it wont be permanent and will only be used while camping, the spare wheel will return there after use, so i would only be using a battery box to hold the battery in place down there.

Can leave wiring there with no battery just make sure its taped up or you remove the fuse because it will be live most off the time.

This will not effect the car at all. as i have a on/off fuse like a breaker i can turn off the rear battery from the front and works fine. I also had the wire hooked up with out the battery there ..fine.

As far as room goes; you might not be able to mount a battery box in the wheel well as there to high. Thats why mine is on its side and no box. These dry cell batterys dont need a box so depending on the size and shape you get just mount some strap points that dont fowl the spare so when you remove the spare just put in battery and strapdown.
then hook up.

Yeah true, if only dry cell batteries weren't massively expensive.
Did you custom make up the power wires for it? What gauge did you use? After looking at a few of them most of them use 50amp fuses inline with it, that should be enough?

Did an edit above

But the fuse size it dependent on weather you plan on jumping the car of the second battery.

I use a 40amp in the front no prob. The rear has a 100amp breaker switch. Was going to put a breaker in the front but got sick of spending money, will do eventually.

Power wire is audio power cable as its got better insulation to protect from upsetting other electrical components as it runs down the middle of the car near my audio stuff. Its also more flexable and easy to work with. My amps draw up to 80 amps so hence the wire is good stuff.

Bought about 5 mtrs and cut to suit. Ring terminals are heavy duty auto crush fit. use a hammer on them.

I will post some more pics ,just took them and need to edit before posting.

will look up my batt supplier there not that dear.

This place seems good on price and my battery is over 2 year old no problem i have a 90 amp hour

http://allpurposebatteries.com.au/shop/index.php?cPath=21&osCsid=d8991e20f1d9aefe1f0e20df1adce12f

My main wire i think is 4 gauge? Any way i do remember its fine for every thing except dual start.

When i left the lights on once i joined the two batterys via switch and it did'nt have enough current to crank.

It did give me back std power. If left for awhile it would have powered up the front battery enough for cranking as the smaller battery at the front will suck power from the larger charged batt in the back itself..thats just how battery's work. Hence why you need an isolation device.

I would have used larger wire but already had heaps this size and its not cheap!

please ignore my sloping wires in att's, Still have tidy up, most are for other accessories.

What size battery would you recommend for just running a fridge, a led light or 2, and maybe a 12v shower pump?
I wouldn't be staying camped for very long in the same spot, maybe 2 days max so the battery would have time to charge inbetween trips again.

That's a tricky question!

You have to work out the draw off each appliance.

A fridge uses very little, i think between 10- 20amp hr. alos depends on temp and how often openend.

Light LED use stuff all.....A shower pump may use a fair bit but is only on a couple times a day etc.

Remember you can always start the car for an hour or so to top up.

I wouldn't go any bigger than 100 amp dry cell as they get to big and heavy for a normal car but more the better.

My 90 amp is the best compromises for power /weight/price etc. but is still bloody heavy as!

Wouldn't go smaller than 75amp min.

remember you may want to use a portable radio, use a 12-240 inverter, tv etc. 12 kettle...

Also a volt gauge would be great as you should never run a battery flat as it kills them asap.

So far i can get about three days of my stereo out of my batt...no amps working still reads 11.8v. Check set up. its still got heaps left in it.
not sure of the current draw.

I've used the keenwood amps all day as well medium volume.(1 day about 9 hours) and seems to only drop to about 11.6 volt from 12.8v. but there big and i would'nt go below about 10.5 volt left as it may take life from the battery.

As a reference my stereo at max draw should only last about 2.5 hrs but that at redickulas volume.

hope this helps.

Also from std ford falcon battery which fits in ours JUST! a weaco fridge will last over a day. They shut down if the power gets to low so mayby run fridge from front battery and go nuts at the back just an option.

yeah im keeping my eye on a local waeco fridge for sale locally atm on ebay, if i win it i will be doing this setup, ive read around and people reckon with a 100 amp hour battery the fridge will run for about 4-5 days, so thats plenty, also found a shower that runs off the heater hoses in engine bay, pretty cool stuff.

That sound about right for the fridge.

My mate got a shower off ebay for his patrol. He goes bush all the time.

He loves it.

They come with different temp units and he upgraded his to work better from the same place.

Sounds like you need a water tank for the car as well! Or a big ass bucket..lol

Luxury camping in a magna..i love it.

To get hot water the car has to run etc so it charges the batts while you do it..bonus.

Make sure you use good adapters and hoses for the shower as there part of the cooling system for the car and if they fail so does your engine!

If you need measurements for my batt 90 amp, as you have pics might give you a better ideal of the size your after let me know. My 90 amp is about the same size as a land cruiser std batt. Handy as the trays are cheap for mounting if needed.

Due the weight my only concern is you mount it right as in an accident they will fly thought a brick wall....or your head!

I worked out a nice way to mount if i had welding skills that would let me do what your talking about and wouldn't even cost much to get done pros. I had heaps off the stuff i used and the batt is permanent so hence my approach.

I Might have to start a camping thread lol

Yeah i watched a vid on youtube showing how to plumb the hot water into the heating hoses, wouldn't want one of them to let go when your driving!
Its all theory at this stage, tossing up whether it would be cheaper to buy a cheap camper trailer or do this myself and have a custom camper that will make people think wtf when they see it haha

looked into camper trailers.

i would like one but im still more satisfied having the basics in the car for now as trailers are over priced.

the camper can have all the other bits but i like the ideal off just going south with the wagon only.

looked into camper trailers.

i would like one but im still more satisfied having the basics in the car for now as trailers are over priced.

the camper can have all the other bits but i like the ideal off just going south with the wagon only.

Yeh they are way over-priced, plus the satisfaction of building something yourself to use beats having something you bought, and i don't wanna pay rego on a trailer every year either.