Battery System

Is there enough space to squeeze a second battery under the hood? Otherwise you may need to put it in the back of the wagon and use a batt. isolator like a redarc for example. Does the camper have a battery? An option could be to mount one on the trailer and run power to the trailer via an anderson plug and isolator.

Leroy

Leroy
Thanks for feedback.

Haven't fully explored the option of a dual battery system quite yet other than general reading on systems such as Piranha, etc and we're trying to keep the costs down. The trailer comes with a compartment for an N70 marine battery which Trak Shak will sell with the trailer along with a compartment for 32l fridge. We want to run a 50l fridge in the car during travel instead of the 32l in the camper (got 3 kids) and then run the fridge from the camper when stopped but unsure of whether the N70 is the best option in regards to amp hours, keeping charged, etc.

Mick
A good system costs more a little more than an inefficient system, how efficient do you want or said in the reverse, how inefficient can you not afford.... and then upgrade

Read each products warrantee and technical information, and then make a reasonable judgement for yourself.

A cranking battery is made for starting a 4x4, however when you read the information supplied by the battery manufacturers you are then informed the best battery to use with a fridge is one that can be often run down lower power than a cranking battery.
Cranking batteries are power rated as Cold Cranking Amps, whereby Deep Cycle batteries are rated as Amp Hours, and made for the purpose of running your accessories....
Yes, they are different....

http://www.uuhome.de/william.darden/carfaq.htm

http://www.rpc.com.au/products/batteries/deepcycle_faq.html

Mick, I would say two things.

1. If there is room under the bonnet for another battery, get a deep cycle, have it wired through an isolator (redarc or similar) from the main starting battery, and run two lengths of 6mm (minimum) sheathed cable through to the back of the car. One to two plugs in the back of the car for the fridge and a light, and one to an anderson plug mounted next to the trailer plug, which will be wired through your camper for lights. Connect pos & neg direct to battery terminals with a 12v circuit breaker, or good fuse on the pos of each. Carry a power cord so you can run the fridge on 240v whenever possible, whether it's in the car or the camper. ( I have this setup in my patrol).

2. Get a battery fitted in the camper, make sure it is properly secured, and wire it through an isolator under the bonnet of the car. (the closer to the main battery the better). Use a minimum of 8mm sheathed cable ( thicker would be better), through an anderson plug connection between car and camper. Get a battery charger for the camper and run it whenever your near a 240v outlet. (my auto sparkie has this setup in his cruiser).

If you are stopping for more than a few days in the bush, both these setups may need a solar panel (expensive but hassle free) or small generator(cheap but you gotta carry fuel) to keep you powered up. (some people run the car at just above idle for an hour a day) (some alternators produce very little charge at idle)

OR....... if you have the money, have BOTH setups.
Better still, get it all !!!!!

In both casses, keep an eye on fluid levels in the batteries, this is sometimes the fastest killer of a good battery, particularly when it's hot.

This is simply my opinion, I am not a qualified anything, and I can GUARANTEE that others will say that I'm full of Siera Hotel India Tango.

Cheers,

Muzz

been through this hell and know what you're going through. i run a 60L Waeco

battery.
buy an AGM (absorbent glass mat) battery. latest and greatest. same technology as the Lifeline and Optima batteries. Recharge in F*** all time. I do drive a GU with a fairly big alternator. but agm batteries charge faster than anything else anyway. Cheaper brands AGM's are remco and FullRiver.. I went with Full river. really happy with it.

battery management unit.
I looked at every option available on the market. from the cheap redarc to the isolated Rotronics to sparkie's own brew. It's easy for people to give opinions when it's not their car. I'm a very picky person and everything has to be perfect.

I went with the TJM's IBS unit. Make sure it's the newest one with the electronic relay unit. The old ones run on a solnoid which was s**t.

new cars of today really can't use these old tech stuff. The beauty of the IBS unit is:
1. The battery indicator on it was absolutely brilliant (in 0.2V intervals). I thought it was a wank factor when i got it but i just spent 2 weeks on fraser island. It was the best bloody tool i had. press a button and you can see how your power consumption is going.
2. the link button. it links your aux and main battery together as one. if your main runs flat or dies, just link the battery with the button and start your car. No jump start to fry your EFI computer. The unit is fully surge protected. Also great when winching, less stress on the alternator. This is the best on the market in my opinion and i would buy it again.

I had guys from OL looking at it thinking their own rotronic battery indicator needs up grading.

Don't know if you have considered this but what's important with due battery system is:
1. is your 50L Waeco a fridge or are you going to run it as a freezer?? it chews up power. get your self a insulation bag. saved me heaps in battery power.
as a freezer running at -6 degrees will yank about 65 amps in 12 hrs. mine was pretty much full all the time and making 3Lt of ice each day.
So a 120 a/hr battery is not very much when you consider you can only use 80% of it so it becomes a 96a/hr battery i use 65 amps that then comes down to 31 amps and a couple of lights for 5 hrs that's down to 21 amps left.
This is all good you may think but the truth is with recharging a battery is that the load to fill is relative to time. The more a battery is drained, longer it takes to fill/top up. even with an AGM.

I have 2 AGM's totally 220a/hrs

2. buy a cheap temp guage inside the fridge, you can run the fridge more efficiently.
3. getting power to your battery, big cable for huge power and fast charge.

If i were you i would consider putting a huge battery in or carry a generator. this all depends on your style of travel. If you trailer will always stay with you, get a 240a/hr battery in the trailer and anderson plug it to run fridge or if you will dump the trailer on some trips then fit the biggest battery you can in the vehicle. under the bonnet is the best. if you put a battery in the cabin, then you'll have to fit an AGM as they emit no gases when been charged which makes it safe.

I gave a huge explanation on all this to another guy on the 4wd monthly forum. It bloody hard on deciding which way to go. took me 7 months to decide with my setup and it's prob the best i could get. It's not the cheapest but it's reliable and useful.

hope it helps.
I'm in brisbane, if you want more info e-mail me and i can point you towards the right people that are awesome fitters.

as you are trying to keep costs down and I suspect there would be no room for a db setup I would suggest putting in the biggest battery you can fit in 600cca+ and using a battery pack as a backup starter. You mention 3-4 day stays you are talking serios aux power required because you are running a fridge. A bit of idling the car might help a bit but nothing compares to a decent drive. It should be ok if you are leaving the ct and driving out to surrounding sites. Otherwise you would have to look at more exy db systems possibly with solar supplement etc etc. (BTW you would be hard pressed to drain a decent battery in one day but any longer than that and you may)