Im looking to set up a dual battery on a 05 Nissan Navara for a trip to Lakefield national park. I have been all over town and asked all the 4x4 stores, battery stores and had a talk with an auto electrician. They all have given me different ways of doing it, with parts and labour for them to do it ranging from $800-1200. I think i will try it myself.

What i need it for... to run waeco cf-50 car fridge average power consumption 0.86 amps/hr at 32degrees ambient temp.
Setup: i want to put the auxiliary battery and fridge in the tray body of the dual cab ute, run the cable down along the chassis and up to the vehicles battery.
The cheapest prices i got were $300 - 100 amp/hr glass mat battery
$149- dual battery kit with solanoid
$90- battery box with fuse

QUESTIONS:
If i buy this gear will it do the job?
Is it safe for the vehicles electrics?
Do i need anything other then what i mentioned?
Also, if anyone knows will the auxiliary battery last, in lake field we will be moving campsite about four times in five days on our way to cook town. with only 50- 100kms of travel a day to the next campsite. Will that charge the battery enough to make the five day trip, and if not what do i need to do this?


Hope this is enough info, any help appreciated

If you want to do it simply, a basic split charge relay is around 20 GBP

Use flexible welding cable, fused at both ends

Caravan bettery boxes are 15 quid or so here , probabily not tough enough so i'd build a vented one in ply

Batteries - wellyou can spend a fortune, friend of mine is looking at 2 oddesy batteries at about 230 quid each ! me , I go to my local farm shop and buy tractor batteries but i do have the advantage of space in my truck

How long will you be driving each day rather than distance is probabily the figure needed to work out recharge

Rich
(ps sorry for uk prices sure you can find local equiv parts & pricing)

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Rich

Iveco Turbo Daily 4x4 40-10
Ex Owner LR101 300Tdi Ambi 'Tiggurr'

First up you need to find out what your existing battery amp hour capacity is. Then buy the leisure battery that has the same capacity - once connected they will attempt "equalise", unless you buy a sophisticated electronic (big$$) charger setup.

Simplest setup is to fit about a 50/90Amp solenoid and a fuse that uses the output signal from the alternator to trigger the solenoid to the on position. The output signal is the one that turns the dash alternator light OFF when power is being produced by the Alternator. This way your vehicle battery is protected from discharge by the fridge, etc.

From the positive terminal of the battery you run a 50Amp cable plus fuse to the solenoid, then from the solenoid to your leisure battery. The neg terminals can be ignored as they will be earthed via the vehicle chassis to each other. You dont need the heavy cable (jumper/welding cables) that is used between the battery and starter as you will not be drawing large current from the vehicle battery to the leisure battery or vice versa.

Depending on the type of leisure battery that you buy will depend on whether its capable of being run down and then recovering - most car starter batteries are not suited to a constant charge and discharge cycle and will fail within a few months. They are not suited to discharge below about 70% - but will vary with maker and type. The purpose made leisure batteries are designed to have a discharge down to about 10% and then recover.

......or;
You could just hardwire the two A/H matched batteries in parallel and put in an isolator switch.
I've just camped with some friends with a split charge set up that they run the Engel fridge off, daily temp was around 24C, they have an Engel volt metre/cut off installed and the fridge ran for 3 days without them starting the engine. Day 4 they were on the move anyhow.
Set the fridge to colder when driving and use a lower setting when camped.
Don't forget to isolate though.
Kevin

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www.4x4-travel.co.uk

Yeah, like RogerM and Rich said. We usually fit/make out own systems. Alternator and relay switch is the easiest. 50amp wire is fine (and 50 amp relay). £50 max for parts plus battery. Maybe a yellow top Optima or similar.
I'm not keen on the National Luna (and others) systems, they can be a pain when they are old and you are trying to find a fault. Good for winching, but still a pain!!
Keep it stupid simple

Oh, you might want to think about solar charging as well, a bit more money but pretty good.

Cheers,
Matt

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www.mattsavage.com
VIAIR - 12 & 24 volt compressors and systems. Tyre levers, Land Rover parts, Sand Tracks, Allisport Intercoolers, Overland Prep, and much more...

my 101 had the national lunar kit installed and it was very good - also the led display was usefull but you could use battery test led sets for that quite cheaply off fleebay or even aldi in the uk

Rich

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Rich

Iveco Turbo Daily 4x4 40-10
Ex Owner LR101 300Tdi Ambi 'Tiggurr'

or just use a volt meter!
like this one,
TIM Superdash 12v Battery Voltmeter Gauge TIM/307 on eBay (end time 23-Jul-09 14:48:05 BST)

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www.mattsavage.com
VIAIR - 12 & 24 volt compressors and systems. Tyre levers, Land Rover parts, Sand Tracks, Allisport Intercoolers, Overland Prep, and much more...

I've been using a cheap caravan leisure battery for the last four years to run an Engel fridge and camp lights (cost about £30?)

Bought a simple voltage sensing caravan split charge relay (£12) and ran some 30A cable from the output back to the battery.

The cable does limit the amount of current that can pass, and it doesn't charge from flat in five minutes, but for road trips where the engine is running for several hours a day it works absolutley fine as the fridge doesn't draw much power anyway.

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www.simba4x4.com

just to echo the solar suggestion, we have a pair of BIG batteries rigged as 24volt, charged via mains, alternator or a pair of solar panels which are also a fair size. In the Outer Hebrides of Scotland (are there any others?!) last winter we almost had to drive every day to maintain charge to run a 50?litre fridge, inside lights, eberspacher, water pump, 100 miles wasn't enough.
St Tropez a few weeks ago, clear blue sky, long days meaning less lighting used, but two showers each a day and the fridge working harder in 35+ daytime 25+ nighttime, we didn't turn her on for a week and lost no charge just with the solar panels
not sure what the weather will be like, and panels aren't cheap, but have a longer life than batteries!!!