09 D22 dual battery setup

[Matt76]

Thanks heaps for the help guys, I have sent this thread a bit off topic but I think there is plenty of good info in here for people anyway.

 

[Jason]

Yeah I am going to put a Ctek on my christmas list I think. They won't overcharge a fully sealed AGM will they?

No it will be fine, a battery will only ever pulll the current it requires to be charged.

I got my CTek from ebay, much cheaper.

 

[Aido]

Ok then.
All of that battery geekery aside then......
Yesterday I had reason to remove the LH side battery and found that there is some sort of "smart" device installed from factory. How do I know? I am hypothesising but
1. With the LH / secondary battery removed the vehicle still has 12v power. Thats nothing spectacular you say because they are wired parallel.....
but
2. If they were indeed in true parallel then the positive cable of the secondary battery would still be live. With the battery removed I put the multimeter across the disconnected +ive cable and ground and got zero. I then grounded the the disconnected cable and nothing. I didn't try this with the engine running but something tells me that these 2 batteries already run some sort of splitting device.
Further investigation required but I am starting to believe that Nissan have actually installed a secondary battery rather than just 2 cranking bats in parallel.

Discuss

 

[Jason]

Hopefully you have some type of smart isolator, it could just be an isolator though.

By smart isolator I mean that it senses voltage levels and cuts in and out at set voltages to maintain a charged 'main' battery, by just an isolator it may cut out when sensing no battery connected.

 

[Aido]

But isn't that the job of a dual battery management system? To do exactly as you described. Ensure that the Main battery maintains voltage to be able keep the vehicle mobile while the secondary can be drained and then replenished by the charging system after the Main has had its fill?

 

[Jason]

Yes, but that's not the difference I mean. I have a redarc smart isolator, if I disconnect the secondary battery the relay will still close and supply power from the main battery if the main bettery's voltage is above the cutout voltage. ie. it will be live and arc out.

You are saying you disconnected the secondary battery and the cable from the main battery was no longer live. This tells me it may just be an isolator that recognises there is no battery and opens the circuit, purely for safety and to stop it arcing.

Clear as mud?

 

[WIR35]

I may have missed something here, but are we saying that D22's come with a dual battery setup standard? I pick my D22 ST-R up tomorrow, however I have never looked at one up close nor test driven one. If it has a stock dual battery setup stock, that would be superb

 

[Aido]

I may have missed something here, but are we saying that D22's come with a dual battery setup standard? I pick my D22 ST-R up tomorrow, however I have never looked at one up close nor test driven one. If it has a stock dual battery setup stock, that would be superb

Yes .
Pop the bonnet and find 2 batteries. How they are setup is under debate.

 

[Jason]

The 09 ones come with two cranking batteries, the change occured when they moved them to the Thai manufacturing plant. The tailgate also changed (flat, no lines) and the tray is now 90mm longer.

 

[Aido]

Yes, but that's not the difference I mean. I have a redarc smart isolator, if I disconnect the secondary battery the relay will still close and supply power from the main battery if the main bettery's voltage is above the cutout voltage. ie. it will be live and arc out.

You are saying you disconnected the secondary battery and the cable from the main battery was no longer live. This tells me it may just be an isolator that recognises there is no battery and opens the circuit, purely for safety and to stop it arcing.

Clear as mud?

Yes Mud it is.
I disconnected what would be the secondary battery (LH / passenger side) all major bits and pieces are attached to the other on the driver side / RH. When I checked to see if they were in parallel and it would seem with the ignition off that the 2 batteries are split. Your arse about with my original description.

 

[Jason]

Ha ha, no my description is fine. I may be using different terminology (being an electrician). In a nutshell, if you have a 'smart isolator' and you disconnected the pos cable from your secondary battery, and the main battery was above cutout voltage, it will arc out/show a potential difference.

One of three things is happening in your case:

1. You have a smart isolator, when you did your tests the voltage of the main battery was below the cutout voltage so it opened the isolator. (I thought this would be unlikely considering the age of your vehicle/battery but you never know.)
2. Your isolator is sensing the battery is removed and opening the isolator.
3. Your isolator may be isolating when the ignition is off. (ie. controlled by the ignition)

I wonder if you can simply swap the secondary cranking battery it comes with to a decent deep cycle battery, that would be an improvement.

 

[WIR35]

Awesome about the batteries, not so awesome about the Thailand part, I was hoping they were still made in Japan.... I was hoping that by getting rid of my D40 I was leaving behind the Thailand quality shortfalls.

I was planning to do a dual battery setup anyway, so that's awesome. I'll do some investigations regarding the battery setup once I pick the car up. I will probably end up modifying it if it's not a true crank + auxillary type setup. Maybe change one of them to a deep cycle and design a relay isolating and charging setup that takes my fancy. It's great that it's all under-bonnet because I was not looking forward to impeding on tub space. Will probably install an inverter under the back seats if space permits.

As for charging setup, I was thinking of installing a small inverter powered from the main battery. This would be switched via a relay, with the relay coil powered by the ignition, with a 30 second on-delay timer (so as to not drain the crank battery before it gets a chance to start the motor and get a bit of charge in it). This small inverter would power a battery charger, the load side of which would be connected to the deep cycle battery. From the deep cycle battery I would run auxillary LED lights (in the future canopy) and a large 240v inverter to power my 240v camping equipment.

I'm an electrician, but don't have a great deal of experience with batteries other than theory and mucking around with cars. In theory this system should work, the deep cycle battery is ONLY charged via the battery charger and is completely isolated from the crank battery when ignition is off. If anyone more learned can see any issues with this setup, feel free to let me know

 

[Aido]

You can carry a 100kw generator behind the back seat - dead space otherwise.
You lost me on the rest of it though.

 

[Old.Tony]

As for charging setup, I was thinking of installing a small inverter powered from the main battery. This would be switched via a relay, with the relay coil powered by the ignition, with a 30 second on-delay timer (so as to not drain the crank battery before it gets a chance to start the motor and get a bit of charge in it). This small inverter would power a battery charger, the load side of which would be connected to the deep cycle battery. From the deep cycle battery I would run auxillary LED lights (in the future canopy) and a large 240v inverter to power my 240v camping equipment.

I'm an electrician, but don't have a great deal of experience with batteries other than theory and mucking around with cars. In theory this system should work, the deep cycle battery is ONLY charged via the battery charger and is completely isolated from the crank battery when ignition is off. If anyone more learned can see any issues with this setup, feel free to let me know

That's precisely how I've got the battery in my caravan set up now, and how I'll be doing the deep cycles in the tub.

Why? Because:

1) Isolating them means no chance of draining the cranking battery
2) Alternator will only charge auto batteries to about 70-75% - and since you don't want to use more than 50% of the battery's capacity (for longevity), it means you've only got 20% of capacity available if you charge from the alternator, and 50% if you charge in the method you've described.

Yes there are losses involved, but none that make any difference in the long run.

 

[Leprechaun]

That's precisely how I've got the battery in my caravan set up now, and how I'll be doing the deep cycles in the tub.

Why? Because:

1) Isolating them means no chance of draining the cranking battery
2) Alternator will only charge auto batteries to about 70-75% - and since you don't want to use more than 50% of the battery's capacity (for longevity), it means you've only got 20% of capacity available if you charge from the alternator, and 50% if you charge in the method you've described.

Yes there are losses involved, but none that make any difference in the long run.

Tony you say an alternator will only charge a battery to 70-75%, but on my setup, (redarc smart solenoid)I always have 12.55V available from my deep cycle battery, which to my understanding is fully charged.
I have being using a Redarc setup (*KISS* principle) for many years, its never let me down, and I've never had any problems with shortened battery life or fast discharge rates.

 

[Old.Tony]

Tony you say an alternator will only charge a battery to 70-75%, but on my setup, (redarc smart solenoid)I always have 12.55V available from my deep cycle battery, which to my understanding is fully charged.
I have being using this setup (*KISS* principle) for many years, its never let me down, and I've never had any problems with shortened battery life or fast discharge rates.

Lead acid batteries are actually 13.8V storage devices, with a charge voltage higher than this. At 14.4V (typical regulated output of a motor vehicle alternator) the most you can get is 70-75% charge, because as the battery voltage starts to rise to meet the charge voltage, the input current drops off and thus the charging process stops.

In order to fully charge a lead acid battery you need to supply it with around 15V. Unfortunately, 15V also causes the battery fluid to fizz as hydrogen and oxygen are released. In a sealed battery this isn't a problem as the gases recombine over time, but in a normal car battery (or deep cycle battery) there are little pin-hole vents in the top of the caps to allow the excess pressure to escape.

When that happens, the electrolyte level (fluid) is lowered, which eventually stops covering all of the plates, thereby reducing the battery's effectiveness.

Another issue with not fully charging a battery is sulfation - crystals form on the lead plates which eventually (through vibration and good ol' gravity) fall to the bottom and, over time, form a circuit between the battery plates. This ends the battery life rather quickly.

Check the Ctek web site - they explain it in much more detail than I do, but that's the basic idea. Alternators are designed to charge the battery only to the point of NOT boiling away the battery fluid, thereby reducing maintenance. Deep cycle batteries are supposed to be maintained more often, so they should be capable of being fully charged more.

 

[pistolpete]

i am thinking of extending the cable of the passanger side battery and joing it to the drivers side battery but changing the battery to a n70 ( this is whats in the early 09 nissan navara which is same engine with out the 2 battery setup). that way none of the wiring is moded and its stil set up the same just getting all its crank off of one battery leaving room to put a deep cell under hood... what are everyones thoughts ?? has anyone done this before?

 

[Old.Tony]

If you join two batteries together, the most important thing to do is ensure that they have identical ratings: both RC (reserve capacity) and CCA (Cold Cranking Amps). If there is a mismatch, one battery will charge faster than the other, signalling to the regulator that it can back off, and neither battery will last very long.

 

[Chriso]

Has anybody installed a dual batt system on a 06ish D22 in the engine bay? i'm just wondering what i'm going to have to move/modify to fit one in? Pictures?
Here's my Bay ATM.
Pictures by chris83topher - Photobucket

 

[Dave]

I am taking some days off in febuary to do all the things I haven't had time to do to my Nav.

I am going another 12 inch battery under the bonnet and removing the prefilter and installing the YD25 snorkel.

Just haven't had the time with work.

Dave.