2nd Battery

[ratstriton]

Thanks for that Buzzy project to do when I pick my vr up which im about go and do ...

[Buzzy]

Make sure we see some pics

[Greedy]

Just dredging up an oldie but why start a new thread.
I'm about to put a dual battery system in and just need some thought on what I'm planning. Given the lack of room under the bonnet I'm going to mount the second battery in the tub. The battery I'm looking at is dual purpose (it's definitely 100Ah and I was quoted by the spotty young fella at the shop 750cca). I will be using a Redarc isolator mounted on the fuel filter bracket using the two tapped holes there to mount it. This isolator comes with a jumpstart function. I am keen to have this function if possible but it leads to my dilemma.
As I understand it, a starter motor will draw something in the vicinity of 200amps. Therefore, if any fuses/breakers are in the system protecting the wiring, they will blow as soon as this is tried. This would mean an unfused run back to the tub. Also, to get the jumpstart working, much heavier cable is going to be needed (25mm) to protect against the current draw and voltage drop. I guess I have to weigh up how often I would use this function as opposed to the risks involved in having unprotected live cable running the length of the chassis into the tub. Can anyone see any other things I have to consider going this way or other ways of achieving this?

The other method is to keep the battery purely as a dual battery without a jumpstart option. This involves smaller wire (probably 12mm) but will have fuses/breakers protecting all runs. This seems the safer option but leads to my second question.
I was planning to use these auto reset breakers:

What happens with them if there is a continuous short? Do they just keep resetting until eventually they break? Are they better/worse than standard fuses?

[craigs]

Here are some pictures of a piranha unit. BTMTD06.






This one only takes a small battery.

[craigs]

In the instructions it indicates the smaller two brackets underneath fit onto some studs already in the guard. My My09 model doesn't appear to have these. Can anyone confirm if these are in place on earlier 3.2 ML Tritons?
I may have to drill the guard or abandon the installation.











Regards Craig

[craigs]

Just dredging up an oldie but why start a new thread.
I'm about to put a dual battery system in and just need some thought on what I'm planning. Given the lack of room under the bonnet I'm going to mount the second battery in the tub. The battery I'm looking at is dual purpose (it's definitely 100Ah and I was quoted by the spotty young fella at the shop 750cca). I will be using a Redarc isolator mounted on the fuel filter bracket using the two tapped holes there to mount it. This isolator comes with a jumpstart function. I am keen to have this function if possible but it leads to my dilemma.
As I understand it, a starter motor will draw something in the vicinity of 200amps. Therefore, if any fuses/breakers are in the system protecting the wiring, they will blow as soon as this is tried. This would mean an unfused run back to the tub. Also, to get the jumpstart working, much heavier cable is going to be needed (25mm) to protect against the current draw and voltage drop. I guess I have to weigh up how often I would use this function as opposed to the risks involved in having unprotected live cable running the length of the chassis into the tub. Can anyone see any other things I have to consider going this way or other ways of achieving this?

The other method is to keep the battery purely as a dual battery without a jumpstart option. This involves smaller wire (probably 12mm) but will have fuses/breakers protecting all runs. This seems the safer option but leads to my second question.
I was planning to use these auto reset breakers:

What happens with them if there is a continuous short? Do they just keep resetting until eventually they break? Are they better/worse than standard fuses?

The largest I have seen in these are about 50 amp.
If you have a look in the Amplifier kit section of some auto stores you may be able to find some heavier duty fuseable links or circuit breakers.

http://www.jaycar.com.au/productView.asp?ID=SF2266&CATID=23&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=461

http://www.jaycar.com.au/productView.asp?ID=SZ6002&CATID=&keywords=breaker&SPECIAL=&form=KEYWORD&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=

Alternatively you can use a combination of circuit breaker and battery switch in parallel. When you aren't jumping, have the switch open, when you need to jump, close the switch to bypass circuit breaker.
I am also looking at mounting a 2nd battery in the tub as an alternative to the bracket I purchased. I am looking to use a combination of the jaycar circuit breaker and the auto reset you have shown in series. If the auto reset breaker fails then the jaycar one will open at a heavier load and stay open.

[Greedy]

I am also looking at mounting a 2nd battery in tub as an alternative to the braket I purchased. I am looking to use a combination of the jaycar circuit breaker and the auto reset you have shown in series. If the auto reset breaker fails then the jaycar one will open at a heavier load and stay open.

Since I last posted, I have done some extra research. I am now going down the jumpstart option but will be increasing the cable from 25mm sq (3B&S or 3 GA) to 32mm sq (2B&S). I also found the 120amp breakers at Jayco so am now the proud owner of 2 of them. I never seriously considered the dual battery trays for under bonnet due to the size restrictions. My second battery is 325mm long so had no chance of fitting under bonnet. I haven't found any answers to what happens to the auto-reset breakers in the case of a continuous short so decided to stay away from them and as you say, they don't go over 50 amp which is useless for jump starting. I really didn't feel like doing extra wiring to bypass the breakers so these 120amp units should do the job well.

[craigs]

See how you go with the breakers, but I don't think they will handle jump starting in any serious way, even in parallel. Keep us informed on how you go with it as I'm still a few weeks off completing my additions.
Regards Craig

[Greedy]

See how you go with the breakers, but I don't think they will handle jump starting in any serious way, even in parallel.

If they can't handle jumpstarting, I found 200amp fuses at Jaycar as well. I've bought a couple in case. Redarc recommend 100amp fuses so hopefully, they know what they're on about. With any luck, I won't have to test this setup out in anger but if needed and the 120amp breakers don't work, I'm sure I could think of something to get me going. I will still have one good battery if the starter battery fails for some reason. I just like things to work at the push of a button.

[Adonis]

Hey guys is anyone going to fabricate a bunch of those dual battery holders and sell them?? they look great but i don't have the time, patience, and resources to make something like this! Would be keen on getting a dual battery set up too. Would it void the waranttee by any chance? If not would anyone be able to tell me where i can get one of those small under bonnet battery holders for an 08 ML trition diesel in western australia???

Cheers!

[Greedy]

would anyone be able to tell me where i can get one of those small under bonnet battery holders for an 08 ML trition diesel in western australia???

Adonis,
TJM have them and the Western Australian branches are listed here
On a more selfish note, I have almost completed my install. It's taken bloody ages but most of this was fiddling around making a box to fit between the wheel arches. I started out thinking that a dedicated battery box is the way to go. This has now changed to a modular drawer system for the tub. The battery box is stage 1 of 3. As I don't usually carry anything that needs tying down, I used the front two tiedown points for anchorage. I didn't really feel like drilling holes in the tub or the liner.
Raw box:

Top of raw box:

After carpet. I still need to carpet and attach the doors to cover the wheel arches:

Top after carpet:

I have run the cables to the isolator (earth terminates at the towbar). It is actually possible to get 25mm square cables up behind the taillight with conduit. Now need to make up a bracket for the breaker/voltge meter either to sit on top of the main battery or on the firewall. I also need a fuse block near the isolator to run spotlights, additional reverse lights and power feed for the PC etc in cab. Wiring also needs to be done for the fridge and additional outlets in the tub. The outlets probably won't be done till the drawer system is finished (about November at my current rate ).

[craigs]

Your a bit further ahead than me Greedy. Doing a similar sort of a cradle behind the cabin in the tub.
I am working on a modular set up for the back of my tub.
I bought some drawers from the trading post and am making my own fridge slide and battery cradle.

[Sapient]

Nice work boys!!

[Greedy]

Craig,
Which way are you mounting you battery? Your frame between the wheel arches doesn't seem to be as deep as mine although my eyes may be out. Having said that, I do have a 42mm border around the base of my battery in an attempt to stop it moving. I will be doing similar to you for the rest of the tub except probably only one draw on the drivers side given the amount of shite we take.

[Tritium]

I will be using two Dynasty 75 ah agm batteries which are 260mm long. I have made the frame just wide enough to fit these nice and snug. I will weld some 25 X 25mm Right Angle into the base of the frame to accomodate and support the batteries and use standard clamps from supercheap to clamp back to the angle. I will fit some cigarette lighter and merrit sockets into it as well as a corded anderson plug to connect to the anderson socket that I will permanantly fit to the inside of the tub.
The drawers I bought out of convenience, but have found them to be quite a good utilisation of space when doing shopping and stuff. The fridge slide is built to accomodate my waeco FF70, I may have to detach the handles or make my own folding handles for it to fit. I will be purchasing Haffele heavy duty drawer runners and make a sliding tray and supports from angle. Hopefully the Haffele runners full extension of 800mm will be enough to get the fridge out far enough to open the lid without it clashing with the canopy or rear window.
The gap under the slide was sized to fit a coleman aluminium picnic table.
I found that the curves of the tub liner reduces the useable amount of space for construction using straight materials like the RHS.
The frames and the drawers will all bolt to each other as needed and I may look at fitting some anchors into the floor of the tub.
regards Craig

[Greedy]

That would explain it. I'm only using one 100 Ah which is 325mm long.

[Greedy]

I found this website has some useful info.

http://www.fridge-and-solar.net/dual_bat.htm

Thanks Tex. It's good to confirm I'm on the right track with the setup.

[Greedy]

Finally got the battery box finished. Added two doors to cover most of the wheel arches.

I still haven't managed to get it connected up yet. Still waiting on a bracket to be made up for the circuit breaker in the engine bay.

[Greedy]

I still haven't managed to get it connected up yet. Still waiting on a bracket to be made up for the circuit breaker in the engine bay.

It's been near on a month I've been waiting for this but still no joy. I guess a "foreign" job at work doesn't really take precedence over anything when you're trying to move a $500M manufacturing business. So I had a go. I have very little in the way of metalworking skills. I ended up buying an el cheapo universal battery tray after discovering the triton doesn't actually have a battery tray. I then cut a sheet of stainless I had lying around to fit the bottom of the tray and also bend up by the rear of the battery. This was braced with some 3mm flat bent to something resembling the shape required. The circuit breaker and fuse box were mounted on this sheet. The isolator is mounted on the fuel pump bracket. All wired up and turned on to discover the isolator wouldn't operate. Bloody Ebay crap. It was supposedly new. 90 bills down the dunny. Sourced another isolator from a local auto sparky for $124. All goes sweet now. Everything added to the car since I've had it (excluding CC and TT) now runs off the 2nd battery. The 2nd battery even charges. Sorry, no pictures of the tray out of the car. It's too ugly to post.
All you can really see of the breaker mount:

Fusebox and breaker. I cut off half the fusebox as there is bugger all room for a camera by the firewall:

Redarc Mounting:

[Skippy]

Hey!

Do you guys think you could post the dimensions of the your brackets or go into more detail with pictures of what points you used to bolt it too?

Cheers

[Greedy]

Sorry Skippy,
Somehow I missed your post. I don't have any of the dimemsions for the brackets handy. The bracket holding the isolator (1.6mm stainless steel) is attached to the leg of the fuel pump near the rear of the battery. There are 2 holes already tapped in the leg of the fuel pump. The bracket holding the fuse box and circuit breaker is just a piece of 0.9mm stainless with a length equal to the length of the battery plus the height of the battery and width the same as the battery. It has a 90 degree bend at the back edge of the battery. The battery and bracket is all held in by the battery clamp. I will try to get the tape measure onto it tonight.