2011 D40 Navara 2.5, Dual battery system

Feldty

Member
May 31, 2012
129
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Wangaratta, Vic
Hi All,

I would like to make everyone aware of an issue in relation to dual batteries on new vehicles in particular my 2011 D40 Navara.

I recently had a dual battery charging system fitted to my Nav by a local auto elec. He used a standard smart isolator and ran the cables directly to the tray. I then had the cable "T" joined to an Anderson plug to charge the battery in the van.

I first noticed an issue with intermittent charging in the rear, and yesterday took the vehicle back to be checked over. It seems that the latest Navara's have an ECU controlled alternator, that will only supply a float charge to the start battery when little power is required. The Alternator seems to rarely supply a higher voltage with the exception of when the engine is first started, Therefore float voltage does not supply enough voltage to make the smart isolator close in order to charge the axillary battery thinking the start battery is low on charge.

It appears that I will need to fit a DC to DC 12v charger and remove the isolators to make the system work. Searching other forums it appears that this issue may also be related to the 200 series cruisers and other newer vehicles. This one is a hard one to detect, as the vehicle charges at the higher rate when first started giving all the indications that the system is working fine.

This system only charged my auxiliary batteries to about 50% without the DC to DC Charger.

If anyone happens to know more about this issue with alternative solutions, please let me no.

Kev
 

straydingo

Well-Known Member
Jul 4, 2011
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Melbourne
There was an article in 'Overlander 4wd' mag (August 2012 page 119) which touched on that

SCAN1088_000.jpg
 

Big Gee

Member
Apr 8, 2011
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The ACT
Hey Feldty,

I've had a bit to do with this. You are right! Most new vehicles run these "smart alternators" in simple terms it is mostly used for better fuel economy!

I have tried the boosting diodes without a lot of success.

The best way is with a dc-dc charger. I run the Redarc BCDC1220-IGN this can switch on & charge from a 6b&s wire running off a relay which switches in our Ranger via acc's power.

Although there is really no cheap alternative it is a super efficient way of charging.

For my two cents worth you will easily return the extra costs of setup by the extended battery life you will receive by properly charging your dual battery.

One more thing, the cheapest alternative if you still want to run a VSR is drive with your lights on all the time! This tricks the alternator into thinking it needs to provide your start and therefore dual battery with proper output power!


Hope this helps
 

Feldty

Member
May 31, 2012
129
7
18
Wangaratta, Vic
Thanks for all the info and comments guys.

It looks like I will need to buy one of these.

http://www.redarc.com.au/products/product/in-vehicle-battery-chargermppt-regulator-25a/

I found one of them from Kulkyn Kampers for $399-. Apparently you need to be careful and ensure you get the LV version (with this style alternator) and not the standard version of these items. The standard ones will still not work with the lower battery voltage and have a similar issue as the Smart Isolator. I am thinking that I may need to fit a Heavy duty solinoid in the +iv wire to ensure the start battery does not get dropped too low when not running.

After contacting Redarc I may need 2 of them. One for the van and another for the dual battery in the tray of my ute. I am hoping to get away with one but I need to do some more research. Currently when the van is connected to the ute, the two batteries are connected together so I might need to give it a go with the charger forward of the "T" join in the wires.

Does anyone know what type of battery is installed in the Jayco's from the factory. These chargers need to be set up battery specific, eg AGM-Gel, Wet Cell or Calcium something.

Thanks again.

Kev
 

Peter D

Member
Jun 12, 2011
52
3
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Brisbane
The redarc dcdc charger has an isolator for the tug battery built into it by the looks of things - so it should for the price.

This thread motivated me to find out what the alternator on my Challenger is supposed to do - fortunately for me it puts out an old fashioned 14.4 volts. I finally finished wiring up an anderson plug today, and I got a reading of 14.39v at the rear of the car, so I'm happy with that.

I think Jayco must use gel batteries unless a different type is optioned - ours came with a gel.
 

Feldty

Member
May 31, 2012
129
7
18
Wangaratta, Vic
Just called Jayco's Parts Department and they informed me that the battery is a gel cell. The AGM that I have in the rear of my ute and the Gel cell can be charged with the same settings so all good.

Peter, I checked further and it appears that there are two styles, one will take an ignition wire that will turn the unit on and off and another works on a much lower volatage and would need a seperate isolator. I will get the Ignition wire on off unit and see how I go.

Kev
 

geoflore

New Member
Nov 26, 2012
1
0
0
Redarc Chargers

Thanks for all the info and comments guys.

It looks like I will need to buy one of these.

http://www.redarc.com.au/products/product/in-vehicle-battery-chargermppt-regulator-25a/

I found one of them from Kulkyn Kampers for $399-. Apparently you need to be careful and ensure you get the LV version (with this style alternator) and not the standard version of these items. The standard ones will still not work with the lower battery voltage and have a similar issue as the Smart Isolator. I am thinking that I may need to fit a Heavy duty solinoid in the +iv wire to ensure the start battery does not get dropped too low when not running.

After contacting Redarc I may need 2 of them. One for the van and another for the dual battery in the tray of my ute. I am hoping to get away with one but I need to do some more research. Currently when the van is connected to the ute, the two batteries are connected together so I might need to give it a go with the charger forward of the "T" join in the wires.

Does anyone know what type of battery is installed in the Jayco's from the factory. These chargers need to be set up battery specific, eg AGM-Gel, Wet Cell or Calcium something.

Thanks again.

Kev


Hi Kev,
I am in the same situation as you were back in May when you posted this. Redarc said I would need two x BCDC1220-IGN chargers. Did you end up going with this option or did you find another solution?
I would really appreciate your advice.......
 

boots33

Well-Known Member
Jun 25, 2011
708
679
93
Maudsland Gold Coast Hinterland Qld
"Smart Alternators" are a real pain when it comes to aux batteries and vans. While the ecu's that control them monitor many circuits to determine how much charge they will allow the main problem for us is when they switch to "cruise mode". Once in this mode the alternator will only output around 13v (the exact voltage does vary from different manufacturers ) which presents all sorts of problems when trying to charge aux batteries.

Once a battery is charged to 80% or more of it's capacity the damage caused by sulphation is greatly reduced and you only need to maintain a charge rate of around 13v to achieve this. So smart alternators use this principal to reduce the drag on the engine.

Now to charge the van battery we are already fighting with the dreaded voltage drop that comes with the run back to the van and add to this a low voltage from the alternator and you can see you are in for trouble. There is also another area of concern and that is running your fridge on 12v while travelling, you will find it may also struggle due to the drop in voltage.

So where does this leave the hapless smart alternator owner? not quite up the creek without a paddle but your wallet may feel some pain to fix the problem . The solution suggested by redarc above will go a long way to addressing the problem. They are probably thinking one unit in the van and another in the tug for the aux battery there. You will need to run your fridge from the van battery to benefit from this setup which will also cause other concerns. The bcdc1220 only supplies a max of 20a and if you have a 150ltr fridge you will be using 15a just to keep it going so there is not a lot left if the redarc has to deal with a run down battery as well. You should also fit a low voltage cutout to the fridge supply to prevent excess battery discharge. Of course this setup will be very expensive to do so there are a few other things you can try first.

As big gee has said above some smart alternators will boost their charge if they detect that the lights have been turned on so this is the first thing you should test. You will need a volt meter to do this and you can buy some really cheap led ones that will plug into your cigarette socket, ebay is a good place to look. Go for a drive on the hi-way and note where the voltage is sitting then after a while turn on the headlights to see if you get any increase in voltage. the increase may not be immediate so drive for a bit .

If you get voltages approaching 14v you will probably be able to do away with the redarc for the van as long as you run with the lights on while towing. you will still need the redarc (or similar dc-dc charger) for the tug aux though, unless you want to drive with your lights on all the time. Stay clear of any vsr type isolation units, you should only use isolators that are directly switched from your ignition circuit.

You may also want to consider a solar panel mounted on the van, this will supplement power coming from your tug and give the added advantage of extended stays off grid. panels are getting cheaper all the time and there are some bargains around if you look.

I would stay clear of the boost diodes as these don't appear to be very effective and i don't like the idea of messing with what can be a very complex system.

For those wishing to know a little more about smart alternators there is a useful article Here on the subject. It is a little heavy going at times but you will get some info gems from it none the less.
 

Burnsy

Well-Known Member
Mar 26, 2012
2,663
977
113
Newcastle
I must of missed this thread but a interesting read, especially after our last trip. I have the redarc isolator for my dual battery and all has been good, the van fridge runs off the start battery through a relay so ignition off no power. I have been leaving my waeco in the tug when we go away running off the aux battery and has been fine, however last time i found it off after about 2 days and the weather was not hot so it wasn't working hard.

When i checked the voltage it read 12.3V, i have the waeco set on med for cut off voltage so that was why, med= 12.3V. Anyway this hasn't happened to me before and i tow with lights on so it maybe an alternator issue for me also, but in saying that on this weekend the tug didn't move so no charge for the weekend, normally it gets a short run somewhere!

Cheers.
 

Feldty

Member
May 31, 2012
129
7
18
Wangaratta, Vic
Hi Guys,
I am glad this thread has re-surfaced.
I have come to a solution with my setup that while is not perfect, it is a compromise between cost and benefit.

I fitted a 105amp thumper removable battery in the rear of my tug (have owned this for a few years now) with a 25amp LV BCDC mounted to the top of the storage box rather than mount the unit to the vehicle. I went down this track because the unit I purchased has a built in MPPT solar regulator as a bonus. I had the van wired to the "A" frame with the thought of charging as we drive, but have left the connector unconnected to the vehicle system at this stage.

When I arrive at a camp I simply connect my thumper to the connector on the "A" frame then connect a 100w solar panel to the BCDC. This seams to back feed to the van battery and eventually even out while being topped up to fully charged by the solar panel. I have no idea if this setup will damage either battery due to the back feed, but so far so good in my limited trials.

For me the perfect setup would be a second BCDC in the van, but this also requires a second 6 B&S wire all the from the start battery. Redarc advise against running two BCDC units in line due to the inconsistent voltage sensing on the unit. Due to finances and the fact that my 150lt fridge seams to work fine on the lower end of the 12v range, with a little luck I hope to get away with the system I have for some time.

For what it is worth I seem to get away with the 105amp thumper, 100amp gel in the van and a 100w solar panel running the van and a 40lt engel fridge. The last time I free camped the batteries were completely solar charged by 10am in the morning but it was sunny. My thought is that solar panels are cheaper to add than alternator charge kits, so if my systems start to struggel, I plan to increase my solar capacity to say 200w.

Can anyone please let me know if they see any issues with the setup as while I have a little understanding of this stuff, I am by far an expert.

"The headlight method failed to work on my 2011 NAV"

Kev
 

Ligedy

Active Member
Oct 13, 2012
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Mackay
There is also another area of concern and that is running your fridge on 12v while travelling, you will find it may also struggle due to the drop in voltage.

...You will need to run your fridge from the van battery to benefit from this setup which will also cause other concerns.

Boots - what are the other concerns to overcome?

I originally planned to run an Anderson plug from the tug battery via isolator direct to my 150L 3-way fridge as most Jayco dealers advised me... until finding out about the smart alternator in my D40.

I now plan on installing a Redarc BCDC1240-LV 40amp DC-DC charger in my expanda to recharge 2 x 100Ah van batteries and then run my fridge off the batteries whilst driving. I.e. running a 6B&S cable from the tug battery to the DC-DC charger in the van and wire the 150L fridge to the van batteries.

Is this ok to do? My concern is - what is the impact of charging the batteries whilst drawing power to run the fridge at the same time? Will the fridge get the right voltage from the batteries? Will this setup reduce battery life?

So many people I have spoken to say don't run the fridge off the house batteries - is this only becuase of the issue with flattening them and thus having no power when you set up camp?

I will put in a low voltage cut off to the fridge supply (if the Setek unit can't manage this) and will also have 2 x 120w solar panels wired to the DC-DC charger for recharging the batteries when stationery or the car switched off... or batteries are flat.

bcdc1240_12v_and_solar_setup.jpg

Not sure how true it is but I have also read:
a) on the Redarc forum - wiring the Anderson negative lead back to the Navara battery can also lead to troubles with some dual battery systems as the Navara computer picks up the voltage and then turns off the alternator... suggested wiring the negative back to the chassis / ground closest to the Navara battery or engine earth to overcome this...

b) there is a mod for the smart regulator issue on the D40's apparently you just cut the green wire at the alternator and the alternator is no longer talks to the computer and puts out constant 14.4V... (http://www.navara.asia/showthread.php?t=6647). I will be installing the DC-DC charger because I want the MPPT reg for the solar and I am hesitant to cut wiring on modern cars... they were obviously there for a reason...
 

boots33

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Jun 25, 2011
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Maudsland Gold Coast Hinterland Qld
what are the other concerns to overcome?

Just the two i mentioned that the BCDC1220 is only a 20a unit leaving little to spare when running a 150l fridge and you should consider fitting a low voltage cutout or perhaps even a movement sensing relay like this. If you use the movement relay you will no longer need to worry about forgetting to turn the fridge off 12v. I should say that with 200ah of battery power at your disposal you will be able to run your fridge for quite a while before you will experience any problems.

I now plan on installing a Redarc BCDC1240-LV 40amp DC-DC charger in my expanda to recharge 2 x 100Ah van batteries and then run my fridge off the batteries whilst driving. I.e. running a 6B&S cable from the tug battery to the DC-DC charger in the van and wire the 150L fridge to the van batteries.
Yes that should be more than enough to do the job


Is this ok to do? My concern is - what is the impact of charging the batteries whilst drawing power to run the fridge at the same time? Will the fridge get the right voltage from the batteries? Will this setup reduce battery life?

Yes this is exactly how it is meant to work. In the redarc manual it says that when a load is applied to the batteries the bcdc1240 will switch from float to boost mode to cover the extra draw and maintain the batteries charge. this will mean optimum battery life and a very efficient fridge.

So many people I have spoken to say don't run the fridge off the house batteries - is this only becuase of the issue with flattening them and thus having no power when you set up camp?

Yes that is the main concern. It can be very easy to forget to turn the fridge off. you only have to do this once to know you don't want to repeat it.


I will put in a low voltage cut off to the fridge supply (if the Setek unit can't manage this) and will also have 2 x 120w solar panels wired to the DC-DC charger for recharging the batteries when stationery or the car switched off... or batteries are flat.

If you have an st-35 setec that has a spare fuse circuit you can use that, this will then use the setecs built in low voltage cutout to protect your batteries. Remember that by the time the cutout point is reached your batteries are already 100% discharged. It is there to prevent excess battery damage by discharging below this point. Solar is a great way to supplement your power needs while off grid. the only issue i can see with how the redarc is wired in the diagram you show is that it will require an ignition feed run from the tug to your van to enable the unit to switch between solar and tug power.


Not sure how true it is but I have also read:
a) on the Redarc forum - wiring the Anderson negative lead back to the Navara battery can also lead to troubles with some dual battery systems as the Navara computer picks up the voltage and then turns off the alternator... suggested wiring the negative back to the chassis / ground closest to the Navara battery or engine earth to overcome this...

b) there is a mod for the smart regulator issue on the D40's apparently you just cut the green wire at the alternator and the alternator is no longer talks to the computer and puts out constant 14.4V... (http://www.navara.asia/showthread.php?t=6647). I will be installing the DC-DC charger because I want the MPPT reg for the solar and I am hesitant to cut wiring on modern cars... they were obviously there for a reason...

I have no first hand knowledge of the d40 wiring setup so can't really comment on the above. I will however repeat that i would treat any home remedies with the due caution they reqiure. As to the earth, while it is generally desirable to run it direct from the battery negative you can run it from other places such as the engine or a solid chassis rail. You must however ensure you have a clean tight connection. If running from the battery negative is not possible another good place is the starter-motor mounting bolts.
 
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boots33

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Jun 25, 2011
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Hi Guys,


Can anyone please let me know if they see any issues with the setup



Kev


Hi Kev

could you supply a little more info. is your van fridge wired through to the tug or is it drawing from the van battery. the wiring to the a frame is that connected directly to the van battery or does it connect to the setec aux in connector.

sometimes it is easier to think in terms of water when trying to sort out battery issues. If you imagine that you have two water tanks one half full and the other full and you connect them together at the bottom by a pipe. when this connection is made the water from the full tank will start to flow to the half full tank. this flow will continue until both tanks have equalised.

This is pretty much what is happening when you hook you two batteries together, except of course it is electrons not water flowing. once the charge equalises flow will stop. During the night your van and engel will draw from both batteries, then in the day your solar will charge into the thumper and from there it will charge the van battery. There should be no adverse effects electrically with this setup. The only things i can think of is
(A) security... how do you secure this setup at nightime. the thumper might wander off if you are not careful
(B) seeing as you have a live battery at both ends of your connection it is important that both ends have a suitable fuse fitted at their respective batteries.
(c) If you are planning long term trips off grid i would definitely be considering extra solar capacity. a few days of rainy weather will significantly reduce you solar output so some extra in reserve is always nice.

congratulations on an innovative approach to solve your situation.
 

boots33

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Jun 25, 2011
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Maudsland Gold Coast Hinterland Qld
I think this thread shows that smart alternators in the end with all their wiz bang "advances" are really quite dumb after all. The sad thing is it should be a relatively easy fix for the designers to rectify. all that would be needed is to add one more wire to be monitored by the ecu. This wire would be connected to your aux battery if fitted , the ecu once detecting power on this wire could switch to a charge mode more suitable to aux battery requirements.... Lets not hold our breath for this solution to appear. :)
 

Feldty

Member
May 31, 2012
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Wangaratta, Vic
Hi Kev

could you supply a little more info. is your van fridge wired through to the tug or is it drawing from the van battery. the wiring to the a frame is that connected directly to the van battery or does it connect to the setec aux in connector.

Hi Boots,

Thanks heaps for the reply, I must admit that I have a little trouble explaining this stuff.

The fridge is wired directly to the start battery with a simple old "dumb" isolator with 6 B&S to the 12 pin plug. From there the fridge is wired as standard supplied by Jayco. The "A" Frame wire is connected directly to the van battery c/w a fuse. Both the Thumper and the van battery have a 50 amp fuse fitted.

Thanks for the explanation on the comparison of electricity to water. That make a lot of sense. I agree totally that I need additional solar capacity (larger water tank). I plan to purchase a second 100w or 120w solar panel kit and wire them together. 200 - 220w of solar should keep us going I hope. The cost of these things has dropped considerably so happy days.
 
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boots33

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Jun 25, 2011
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The fridge is wired directly to the start battery with a simple old "dumb" isolator with 6 B&S to the 12 pin plug. From there the fridge is wired as standard supplied by Jayco.
Well thats about as good as you can get it without spending a lot more cash. I agree with your earlier post that if it works as it is then why spend more.

The "A" Frame wire is connected directly to the van battery c/w a fuse. Both the Thumper and the van battery have a 50 amp fuse fitted.
Yep that is good too. By connecting directly to the van battery you avoid the .6v drop through the setecs blocking diode, not a lot but every bit helps in your situation.

I think all of us are pleased with price drops on solar panels
 

POD

Member
Dec 18, 2012
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Newcastle Region
OK, so to combat these so-called "smart" alternators, why can't we "dumb" it down? Here's my idea/plan: if you run the positive power from the starting battery (instead of the alternator) to the relay, which then goes to the auxiliary battery, why won't that work? You are taking voltage from the starting battery, the alternator will sense a drop in the starting battery's voltage and then increase its output to the starting battery, which will then charge the auxiliary through the relay.

I know it sounds too simple but why won't that work?

Also, has anyone actually run a volt meter on their starting battery to make sure that what you are being told is the truth and not just some guys attempt to up sell you a new whiz bang dc-dc charger??
 

Thirstyviv

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Jan 8, 2012
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Well done POD my thoughts exactly. I had that system for my Triton to my Redarc isolator, wired up to the Anderson plug that feed into my Expanda and all in all I was getting 14.39V to the van to charge the battery.

I mean I'm no electrician but it worked for me.