Variable Voltage Alternators

[~Rich~]

Hi all,
We had our 4wd club meeting at Battery Business in Warriewood, it was very interesting with a discussion about the newer vehicles having variable voltage alternators.

Variable Voltage Alternators
Some vehicles released in late 2010 onwards with common rail diesel and petrol engines have variable voltage alternators that are on the vehicle CANBUS. These alternators vary output based on driving conditions at the time. The range of voltage can be between 12.3V and 15V For this reason, the alternator may not charge a dual or multi auxilary battery bank at all times, and may apply too high a voltage for the auxliary battery chemistry type at other times.
Known vehicles with this style of alternator - Nissan Navara D40, R51 Pathfinder 2011 onwards V6 Diesel only. Hyundai Santa Fe 2010 +, Range Rover 4 2011 +, Ford Ranger 2011 +, Pajero 2012 +, Mazda BT-50 2011 + and Land Rover Disco 4, Isuzu D-Max 2012.

This question is probably best answered by Tim / Drivesafe.
Is the standard SC80 suitable for the latter model D4 / RRS?

[sheerluck]

Tim does sell specific D3, D4 and Range Rover kits with the SC80, so I would very much assume that the SC80 is suitable.

[bbyer]

This variable voltage design concept appears to have been around for a few years now, but only on select vehicles, our 3's and now the 4's being part of that advanced group. VW Phaetons and the Bentley are as well.

It seems these electrical systems are characterized by what is called Pulse Width Modulated signals from the engine computer, (really the car computer), telling the alternator and associated loads what to do. It seems to be an emissions related thing; rather than increase alternator output, the radio amplifier will be told to go to sleep or perhaps the heated seats cycled - load management it is called.

The looser in all this seems to be the battery; charging it seems to be last on the list or priorities, hence why a dual battery system seems to be a requirement, not a luxury.

I think the Traxide people were in the forefront of realizing the unusual characteristics of the 3's electrical system and hence their units are designed to accommodate the peculiarities of CaCa battery's and their related PWM charging systems.

Volkswagens solution is to provide a "free" CTEK charger with every Bentley, at least over here anyway, along with instructions to use it monthly, and better yet, weekly.

The design is showing up on garden variety Ford pickups here now as well - seemed to be a Ford and VW thing initially.

[letherm]

.

The looser in all this seems to be the battery; charging it seems to be last on the list or priorities, hence why a dual battery system seems to be a requirement, not a luxury.

I think the Traxide people were in the forefront of realizing the unusual characteristics of the 3's electrical system and hence their units are designed to accommodate the peculiarities of CaCa battery's and their related PWM charging systems.



After reading various threads over the last several months I have been wondering whether to fit a Traxide system to my 4 month old D4 but don't have any auxiliary requirements - fridge etc. My concern is not to be left stranded. Are they a nice to have or a must have?

Drivesafe, I know you sell them, but I would appreciate your input.

Martin

[vs2]

Exactly the reason I put mine in, 6 month old D4 stranded with a flat battery. So just for peace of mind I installed the Traxide US160 with jump start. I now know that that with a flat cranking battery I can still get it started. Easy to install, took me an hour.

http://www.aulro.com/afvb/attachments/technical-chatter/73634d1393804881-second-battery-rubber-boots-terminals-p_20140227_094717-copy-.jpg

[drivesafe]

Hi folks and sorry for taking so long to reply but I am flat out with orders ( and behind ).

The reason I mentioned to the orders situation is because more and more “OTHER” makes are finding my system allows good charging of all batteries connected to the vehicles electrics.

Hi Rich and I bet the company was advising the installation of DC/DC devices to supposedly “correct” a problem that doesn’t actually exist in most new vehicle.

Here is some info you can take back to your club.

All new Nissans have variable voltage operation, BUT all you need to do is go to the back of the alternator and find the loom with a number of thin wires coming out of it.

One of these wires is GREEN, simply come out a bit from the alternator and cut that green wire. The Nissan alternator will now operate at a constant 14.0 - 14.2v at all time.

Pajaros, BT-50s, Colorados, Amaroks, Toyotas and all Land Rovers will have no problems charging and maintaining banks of batteries when using one of my isolators.

There is a bit of a catch with the Toyotas. Anything between late 2009 to early 2013 will most likely need an Alternator Voltage Booster Fuse, made by a guy in Melbourne.

From 2013, Toyota raised their operating voltage levels but they can still benefit from the addition of an Alternator Voltage Booster Fuse.

Rich, hope this is of some help to your club

[letherm]

Exactly the reason I put mine in, 6 month old D4 stranded with a flat battery. So just for peace of mind I installed the Traxide US160 with jump start. I now know that that with a flat cranking battery I can still get it started. Easy to install, took me an hour.

http://www.aulro.com/afvb/attachments/technical-chatter/73634d1393804881-second-battery-rubber-boots-terminals-p_20140227_094717-copy-.jpg

Is the Jump/Normal switch part of the system? If not where is it from?

Martin

[sheerluck]

Is the Jump/Normal switch part of the system? If not where is it from?

Martin

It's standard. Read all about it here: USI-160 - 160 amp Winch Isolator | TRAXIDE - RV | Traxide - RV (http://www.traxide.com.au/isolators/usi-160---160-amp-winch.html)

[~Rich~]

Thanks Tim, yes that explains it perfectly.
You are at the forefront of your game. ;)

[josh.huber]

Tim's stuff is all great I have wired up a abg25 cut out to my mates boat so that an alarm goes off when the house bank reaches 12v saving 3 batteries works perfectly.

[winaje]

Is the standard SC80 suitable for the latter model D4 / RRS?
I'd be interested to know this, particularly as I have a 3 or so year old SC-80

[phl]

I'd be interested to know this, particularly as I have a 3 or so year old SC-80

I should hope so, as that's what Tim sold me for my MY13.

The D4-2S is listed as being the kit for the D4.

[drivesafe]

Hi again folks and if you fit any other VSR ( Voltage sensing Relay ) type isolator in any of these Low Operating Voltage vehicles, you will NOT charge auxiliary/house batteries anywhere near as well ( if at all ) as what my isolators achieve.

The reason for this is that most new vehicles with Low Operating Voltage, carry out some form of cranking battery analysis immediately after you start the motor.

The Battery Management System ( BMS ) can do this in a number of way but basically the BMS keeps the alternator’s output voltage at a low specific level and monitors the amount of current the cranking battery draws.

From the data gained, the BMS will then set both the initial BOOST charge cycle, where the voltage is run at a high level for a given time, and then the NORMAL operating voltage will also be set to optimise the cranking battery’s ability to get a decent charge while the motor is running.

Now for the difference between what my isolators achieve and what other isolator can not.

When you have been driving around town, with no accessories drawing power from your auxiliary battery, the two batteries will be ( should be ) near fully charged.

When you turn the motor off, with any other isolator, the isolator cuts out when or shortly after the motor is turned off.

My isolators remain cut-in ( ON ).

When you next start your motor, no matter which isolator you have, the BMS will see the cranking battery is near fully charged and will run a minimal short BOOST charging cycle.

No problems so far for any type of VSR type isolator.

Now you go on a trip and the same thing, you turn the motor off and then or a short time later, your ordinary isolator cuts out and you run your fridge, camp lights, camera and phone chargers off the auxiliary battery.

A few days later, when you are ready to go home or move to another camp site, you start your motor and because the cranking battery is still in a near fully charged state, the BMS, has no reason to set anything but a short BOOST charge cycle and then it lowers the voltage down to the normal low operating voltage.

So any low auxiliary/house batteries don’t get anywhere near the charge they need.

Now the same scenario using one of my isolators.

When you arrive at your campsite, your turn off your motor but this time, my isolator remains on ( cut-in ) and your accessories run off ALL your batteries, including your cranking battery.
If the power used, while you were camped, does not discharge your batteries down to 12.0v my isolator will remain on.

If the total power used discharges the batteries down below 12.0v, at 12.0v my isolator cuts out, leaving your cranking battery with 50% of it’s total capacity available to start your motor when needed.

When you start your motor to move to the next site, or go home, the BMS does it’s job.

But this time, after analysing the cranking battery, the BMS determines the cranking battery is in need of a charge, and sets up a different BOOST charge cycle, where the voltage is higher and/or longer during the BOOST cycle and it also may not take the voltage as low as it usually does in the normal low operating voltage level.

Because the BOOST cycle is higher and long, ALL batteries in the system receive the BOOST charging.

SIDE NOTE, there is a misunderstand that people have, that an alternator stops charge or lowers the charge CURRENT, once the cranking battery is full.

This is not so and an alternator, even with an advanced form of BMS, only alters it’s voltage. The amount of current being produced is based on the load being applied to the alternator at different voltage levels.

EG, if at a voltage of X the cranking battery is applying a 20 amp load on the alternator, the alternator will produce 20 amps a voltage X.

If you add another battery load which also places a 20 amp current load on the alternator when it’s at voltage X, the the alternator will now produce 40 amps.

This means all batteries connected to the alternator will receive a decent charge voltage and charge current.

With the way my isolators work, there is an additional charging advantage.

Because the ACCESSORIES load applied to the auxiliary battery is SHEARED with the cranking battery, if you use the same amount of power as you would with an ordinary isolator, with my isolator, your auxiliary battery will not be discharged anywhere near as low as it would have to be, when using an ordinary isolator.

This means, with my isolators, you batteries are not only going to charge properly, they are going to charge in roughly one third less driving time.

Hope this explanation helps to show why my isolators work so well with these new low operating voltage type vehicles, when other types of VSR isolators do not.

[bbyer]

I'd be interested to know this, particularly as I have a 3 or so year old SC-80 I realize the quote is in reference to a D4 but I have been asking myself somewhat the same question related to my LR3 - should I upgrade my "classic" SC80 to one of the newer units? Different units do different things, so any of the units including the old ones are still good, but it depends upon what you wish to achieve.

In my case, the model I was considering is that one with the switch. Having the option of being able to manually join my two battery's together for starting purposes has some merit in this country - snow yesterday and this morning, the official first day of spring, it is -10C, cloudy and windy. I do not need the winch feature, (no winch), but just that "jumper" feature beats fumbling with a booster cable from one to the other in the cold and dark.

At the same time, I would want the switch and LED to "look pretty" inside the cabin and while apparently I can install my own setup, from the web site, it is not yet clear how. I guess if I get serious about it, I will follow up and find out just how to wire it and what is needed for the LED as LEDs come in many flavours. In the mean time, I will figure out where I would install the switch and LED in my 3. At least the D2's had extra spaces for additional switches.