Dual Batteries in new tug

DavidMMc · Member

Dual Batteries in new tug

TimTim · Guru

Hi David, firstly what size and type of batteries are you having in the van and is there some sort of battery charger/ solar controller. I wont use the term battery management system which has been adopted by one company because a BMS is what you will find in a lithium battery.

I suspect you have some some of charger installed as you have solar so can you give us the name and model number of what is installed in the van. Unless you intend going away for a few days in just the tug with a fridge etc then you may not need a second battery installed.

An example of this is I have a Redarc Manager 30 Whichever they call a battery management system. It is a DC/DC charger, 240v charger, solar controller and battery disconnect etc in one system. You may have something similar. I dont go camping without the van so i dont need a second battery in the tug.

Tim

Mike Harding · Guru

I can not see a reason why you need dual batteries in the tow vehicle. Normally one may do this for a 4WD which goes off-road (no caravan) and requires extra power for fridges and the like but you have a caravan and its associated electrics to perform that task.

Leave it as it is is my suggestion.

Clarky 1 · Senior Member

My view for what it is worth is if you are having a fridge in the tow vehicle then I would install a second battery charged with a Dc Dc charger from the vehicle alternator.
If you arent having a fridge then I wouldnt bother unless you have some other dedicated use for the extra battery.

Whenarewethere · Guru

I would only put a second battery in the tug if you have a separate fridge in there & you are doing day tours etc.

If you provide a list of your setup we can advise our personal views, which differ greatly. Then you can make executive decisions.

Aus-Kiwi · Guru

Is there any chance you could use up all the battery and cannot start in the morning ? Even in Motorhome this is a concern . Like a fail safe system ! Besides if your luck is anything like mine ? It will happen At the worst time !! 1000s of Ks from anywhere !! Depends where you intend to go etc ?

TimTim · Guru

Aus-Kiwi wrote:
Is there any chance you could use up all the battery and cannot start in the morning ? Even in Motorhome this is a concern . Like a fail safe system ! Besides if your luck is anything like mine ? It will happen At the worst time !! 1000s of Ks from anywhere !! Depends where you intend to go etc ?

You need one of these biggrin

https://www.4wdsupacentre.com.au/adventure-kings-1000a-lithium-jump-starter.html

dogbox · Guru

what will the second battery be used for ?

i have a second battery in the canopy of the ute it is basically there to supply power to a fridge an some 12 volt accessories when away from base and it is charged up by a solar panel on the roof, totally isolated from ute's electrical system. total cost of the system from kings around $400, battery, battery box , solar panel (simples). i went this route as the ute only drives mostly short distances an could be sat in one place for a few days , so a dc to dc charger was not a real option for an additional cost of $350 +

-- Edited by dogbox on Wednesday 20th of July 2022 07:36:13 PM

Aus-Kiwi · Guru

I need two good 12v batteries to start my GM 6.5 Detroit in my case

rgren2 · Guru

Aus-Kiwi wrote:
I need two good 12v batteries to start my GM 6.5 Detroit in my case

Interesting, I only require one. confuse

The Travelling Dillberries · Guru

I have a 50l fridge in the tub of my dmax, it can and does get removed occasionally. If I don't remove it when we park up I plug it into the van Anderson which is connected to the van batteries, which are solar charged. So I agree with Mike.

The option is always there to plug into 240v at C/parks.

I have been using it this way for seven years, never thought i need a second battery.

Aus-Kiwi · Guru

To me its like like going without a spare tyre ! Ive had batteries go down enough that I dont have enough voltage to start engine . Thank goodness I have a system I can parallel. Plus I often free camp way out in the middle of WA or Queensland .

rgren2 · Guru

Aus-Kiwi wrote:
To me its like like going without a spare tyre ! Ive had batteries go down enough that I dont have enough voltage to start engine . Thank goodness I have a system I can parallel. Plus I often free camp way out in the middle of WA or Queensland .

Slightly OT, but I do have a dual battery system, but I havent wired them to link for starting (just a wire and switch). I do carry this though, itll start the 6.5 eve when its cold.

Whenarewethere · Guru

The starter battery I simply do not attach any accessories which will flatten the battery. Too many overloaded accessories in modern cars. Up to a 210 amp alternator in my car depending on model.

I can jump start if necessary from my auxiliary batteries with welding cable jumper leads with 175 amp Anderson plugs.

The cable is multipurpose, also using it for compressors & an utterly overkill extension leads for solar panels if desperate for a few more metres to reach some sun.

Just the other day I jump started another car in our street. While at it out of interest I stuck on my DC clamp meter. The Audi 6 cylinder diesel needs 344 amps.

My 2.0L petrol turbo needs 238 amps to start.

Aus-Kiwi · Guru

With elect injector pump ! Its not mechanic injection . Even if it turns over they wont start ! Most go back to older mechanical injector pump . Does away with all these issues !! One of the first electronic ECU controlled diesel systems . Before single rail . At times US is slow at taking up good tech !!

Warren-Pat_01 · Guru

Hi David,
Unless you travel separated from your caravan, you won't need an auxiliary battery if your car/caravan is wired as per normal using a Redarc Relay.
We do occasionally & run a smaller car fridge so I have a combination use battery in the tub (it's cooler there than under the bonnet). It is fed by a CETEC DC-DC converter. I also utilize it to feed the fridge in the caravan while we're travelling & carry a jump starter in case of a flat battery (it works).

When I had my Patrols, I became an expert at cooking aux batteries! Toyota had more brains than Nissan as to where they fitted their batteries - right up the front.

Whenarewethere · Guru

At least you can fit a second battery. I only have room for one but at least it is divided off from the engine with reasonable air circulation. So I had to resort to 26AH batteries stuffed around the car, 2 fit under a seat.