why is alternator outputs being limited in new vehicles

Submitted: Wednesday, Feb 20, 2013 at 08:08
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i understand that some new vehicles have alternater outputs that just replenish the charge used by starting,eg ford and merceedes.(the local merc dealer has had a number of new vehicles with flat batteries)
Can anyone explain why manufacturers are doing this???
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Reply By: Peter_n_Margaret - Wednesday, Feb 20, 2013 at 08:47

Wednesday, Feb 20, 2013 at 08:47
To reduce fuel consumption.

Cheers,
Peter
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Follow Up By: Member - Beatit (QLD) - Wednesday, Feb 20, 2013 at 09:42

Wednesday, Feb 20, 2013 at 09:42
Seems to be a bit of a trend in Euro vehicles (wasn't aware of the alternator governor) but recently hired an Audi that stops the egine when stopped at the lights and restarted when I lifted my foot of the brakes. My thoughts were that the fuel saving would be mediocre and the potential future problems huge. I suspect that cars like this will be worthless at say 10 years because all the gizmos just too expensive to fix - guessing we are heading to a disposable car for the benefit of fuel economy, not sure if we will be ahead in the end!

Kind regards
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Follow Up By: pop2jocem - Wednesday, Feb 20, 2013 at 11:27

Wednesday, Feb 20, 2013 at 11:27
Not sure if you and me will be ahead in the end but I suspect the vehicle manufactures will and probably the state governments as they get to collect stamp duty more often.

Or am I just being cynical??

Cheers
Pop
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Follow Up By: Ross M - Wednesday, Feb 20, 2013 at 11:46

Wednesday, Feb 20, 2013 at 11:46
No pop just realistic. No cynicism at all.

The next step in vehicles will probably be the switching off of airconditioning on hot days.
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Reply By: Nomadic Navara - Wednesday, Feb 20, 2013 at 09:39

Wednesday, Feb 20, 2013 at 09:39
They are having to do it to meet the new emissions regulations in other countries. Better fuel consumption means less emissions.

You mentioned ford and Mercedes. Most of the new vehicles are going that way. I think it was about 3 years ago that I heard that the Hilux alternators were only putting out a voltage down near 13 V. Direct charging of auxiliary batteries through isolators is nearly a thing of the past. For any new vehicle,plan on fitting a DC-DC charger for your auxiliary battery.
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Follow Up By: Member - Geoff M (VIC) - Wednesday, Feb 20, 2013 at 10:27

Wednesday, Feb 20, 2013 at 10:27
You are correct about all manufacturers now doing this. Depending on your application, there is an alternative to an expensive DC-DC charger and that is fitting a voltage boost diode in the sense line for the alternator. This is just replacing the ALT-S fuse with a fuse-diode arrangement hence boosting the voltage by 0.6V.
There are plenty of previous posts about the positive and negative aspects of this, and if your second battery is a fair distance away from the main battery & alternator then definitely look at the DC-DC charger option.
Again I stress it is "horses for courses" so make a informed decision based on your individual requirements. Be wary of information from many of the so-called experts in 4WD stores who will gladly sell you a over-the-top expensive system.

Cheers, Geoff
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Follow Up By: Allan B (Member, SunCoast) - Wednesday, Feb 20, 2013 at 11:29

Wednesday, Feb 20, 2013 at 11:29
Fitting a "voltage boost diode" in the alternator sense line is not possible with "intelligent" charging systems. There is no simple sense line. The alternator voltage is controlled by a PWM signal from the Engine Management System.
Cheers
Allan

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Follow Up By: Member - Geoff M (VIC) - Wednesday, Feb 20, 2013 at 12:11

Wednesday, Feb 20, 2013 at 12:11
Hi Alan,
You are probably right - I can only speak for the vehicles I know about such as the current model Landcruiser series (Prado, 70 series, 200 series) and the Alt-S diode works a treat on these.
Perhaps other vehicle owners need to check further and if they have a sense line then the voltage boost diode could be an option.

Cheers, Geoff
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Follow Up By: olcoolone - Wednesday, Feb 20, 2013 at 20:56

Wednesday, Feb 20, 2013 at 20:56
Do you think if it was a good idea to increase the charge voltage; the manufacture would of done it to start with?

So why don't the manufactures just increase the voltage to start with.....

The amount of voltage increase seen with the diode mod is about .5v max.... still not enough to keep a AGM in good shape and fully charged.

People spend $200 plus on a battery and they skimp with a $40 mod that costs less than $2 to make that doesn't work to 100%..... funny people 4wders are.....!

Bit like trying to sell treated effluent to the Eskimos...
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Follow Up By: Member - Geoff M (VIC) - Thursday, Feb 21, 2013 at 07:37

Thursday, Feb 21, 2013 at 07:37
Olcoolone - You obviously have an electrical background and know a lot about charging systems, I think NOT! How does the normal start battery maintain its charge, is there an expensive 5 stage DC-DC charger driving it?
If you had bothered to read the post properly I stated that each situation needs to be evaluated properly and the right choice made for a multiple battery system. In some cases a simple solution such as maintaining the voltage that the alternator outputs by the use of the sense line is the best solution.
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Follow Up By: olcoolone - Thursday, Feb 21, 2013 at 08:26

Thursday, Feb 21, 2013 at 08:26
Know nothing about electrical...... just read a lot on the net and pick up truthful advice from people like you.

Seeing starter batteries are charged to 100% SOC from your standard charging system as you have indicated..... that means the aux battery will be charged the same.

So no need to increase the voltage...

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Follow Up By: Nomadic Navara - Thursday, Feb 21, 2013 at 14:36

Thursday, Feb 21, 2013 at 14:36
Quote "Know nothing about electrical...... just read a lot on the net and pick up truthful advice from people like you."

60 - 75% of what appears on forums is not accurate. 40 - 50% is getting far from accurate. 10 - 12% would be misleading and dangerous. Are you trying to increase those percentages? Without an electrical background how do you sort the wheat from the chaff? Unless you do considerable study in non forum or web based areas I suggest your information is not worth a cracker. There are already too many in forums parroting what others have posted whether it is appropriate or not.

Quote "Seeing starter batteries are charged to 100% SOC from your standard charging system as you have indicated.."

Drivesafe and his cronies are the only ones who believe this.
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Follow Up By: olcoolone - Thursday, Feb 21, 2013 at 18:27

Thursday, Feb 21, 2013 at 18:27
And ????......
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Follow Up By: Rockape - Thursday, Feb 21, 2013 at 18:52

Thursday, Feb 21, 2013 at 18:52
2 times And ??????.......
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Follow Up By: The Bantam - Thursday, Feb 21, 2013 at 22:29

Thursday, Feb 21, 2013 at 22:29
The reality is this.....the vehicle that the diode fuses will work in will not be vehicles with minimised charging.

the good reason for the diode is.

In the past charging systems typicaly charged at 13.8 volts....because standard screw top batteries where used...if a higher charge voltage was used excessive electrolite loss would occur.

Most of the modern vehicles post 05 come fitted with sealed maintenance free batteries.....that have calcium in the plates and modified electrolite that allows gas recombination and the battery to be sealed.

These batteries will tolerate higher charge voltages and will not suffer electrolite loss.

Thus later model vehicle may have charging voltages of arround 14.2-14.5 ish volts.......if you buy a replacement alternator it will probaly charge at arround the 14.2- 14.5 volts.

This change can be achieve quite safely in some 13.8 volt alternators by fitting a fuse diode resulting in a charging voltage of arround 14.2 volts.

This is a different point to the OP....but that is the why and the wherefore.

cheers
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Reply By: Allan B (Member, SunCoast) - Wednesday, Feb 20, 2013 at 11:24

Wednesday, Feb 20, 2013 at 11:24
The new "Intelligent" alternator control is intended to reduce fuel consumption and emissions in several ways.

1) The alternator output (and hence engine load) will be reduced or even ceased during acceleration to provide more power (at any given throttle) to the vehicle's wheels.
2) The alternator output will be reduced to zero during idling to reduce engine load and emissions.
3) The alternator output will raised during engine braking during deceleration to provide regenerative charging.


Projected fuel savings are 3%.



AGM cranking batteries are being introduced to allow for a more cyclic charge pattern and will frequently be operating at about 80% SOC.


Articles on this subject are hard to find on the internet without access to authoritative professional sites and some uninformed information exists.
I cannot reliably determine how this new alternator control will affect the charging of auxiliary batteries but it seems likely that at least DC-DC charging will be required and even that will need some special attention by the manufacturers. It is also possible that third parties may offer vehicle modification solutions.


Cheers
Allan

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Follow Up By: Allan B (Member, SunCoast) - Wednesday, Feb 20, 2013 at 17:10

Wednesday, Feb 20, 2013 at 17:10
After studying Redarc's technical specifications it would seem that they have addressed the aspect of 'adjustable-voltage' alternators controlled from the ECU. They have achieved this by changing the 'Turn-on' setting from 13.2v to 12.0v and the 'Turn-off setting from 12.7v to 11.9v.


In order to ensure that the charger switches off with a stopped engine, even though the input to the charger may be maintained above 11.9v the Blue voltage-sensing wire is connected to an 'ignition' source rather than to the charger input.


The thing that is not clear is that some Redarc BCDC chargers having these new parameters are identified by a model suffix '-LV' and others with the suffix '-IGN' so it would be easy to order an incorrect model.


Incidentally, I left a condition out of my post above. It was:-

4) The alternator output is adjusted in accordance with the battery temperature.




Cheers
Allan

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Follow Up By: olcoolone - Wednesday, Feb 20, 2013 at 21:16

Wednesday, Feb 20, 2013 at 21:16
Allan.... the LV is a low voltage input model and the ING is an ignition switched model.

The BCDC-IGN operates purely on an ignition input, switching the unit on and off with the vehicle ignition.

The BCDC-LV variant features lower voltage settings so that it can continue operating with a low input voltage from the alternator and also still utilise the blue input select wire so a solar input can be selected
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Follow Up By: Allan B (Member, SunCoast) - Thursday, Feb 21, 2013 at 00:15

Thursday, Feb 21, 2013 at 00:15
Olcoolone,



You are lecturing to the informed.
They are both low voltages models designed for use with variable-voltage alternators.


I attach here the wiring diagrams and Voltage Threshold tables for the Redarc BCDC1220-IGN and the BCDC1225-LV chargers. These were lifted directly from Redarc's product pages. If you look carefully you may observe that there is no difference in either the wiring diagrams or the threshold tables. In fact one could believe that Redarc has in fact used the same documents in each variant instruction. Changing only the title etc. Each of these models has the same threshold settings and each of these models requires the blue wire to be connected to an ignition controlled circuit when the charger is being used to charge the auxiliary battery from an alternator. Or switched via a relay when a solar input is also being used. (Alternate diagram)
Incidentally, the ignition input does not "switch the unit on and off". It merely enables or disables it. The threshold settings switch it on or off.


They are both Low Voltage models and they are both ignition enabled.
So why does Redarc use differing model suffixes?
Can you see my point now?
If you still are doubtful, do your homework and look in Redarc's website for yourself.








Cheers
Allan

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Follow Up By: olcoolone - Thursday, Feb 21, 2013 at 09:48

Thursday, Feb 21, 2013 at 09:48
Sorry Allan..... thought speaking to you you would understand, I'll explain it a bit better.

"ING" and "LV" are nearly the same....

The BCDC1220 can come in two versions, the standard voltage sensing type and the ignition sensing type.... standard for normal older charging systems and ignition for the newer ECU controlled charging systems.

The BCDC 1225/40 come in standard for normal older charging systems and LV for the newer ECU controlled charging systems..... the difference between the 1220 ING and the 1225/40 LV is the blue wire on the 1225/40 has a dual function of switching it on and off as well as controlling a relay to switch between alternator charging and solar.

So the ones for newer ECU controlled charging systems with a solar MPPT regulator are called LV (1225/40) and the one with no solar MPPT regulator are called ING (1220).

Both LV and ING require switched 12v+ to the blue wire to work..... the standard ones uses voltage sensing to turn on..... with the standard one you still have to connect the blue wire to a 12v+ source but it doesn't have to be switched..... in a standard install when using the standard version we connect the blue voltage sensing wire to the input wire.

The turn off and on voltage on the "LV" and "ING" models is the voltage the BCDC will turn off and on at when the unit is switched on from an ignition source...... The "standard" BCDC will auto turn off and on once a set voltage is achieved.

The low voltage cut out is a safety device.


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Follow Up By: Allan B (Member, SunCoast) - Thursday, Feb 21, 2013 at 11:54

Thursday, Feb 21, 2013 at 11:54
Olcoolone,



Yes I already know all that. Can you not see that from what I have said?
BTW, it's "IGN" not "ING".



The point is that there is no construction or application difference between the LV and IGN models. They both have the same thresholds and they both require "ignition" sensing, so why does Redarc confuse the public by using differing model suffixes? Maybe I should ask Redarc.


Anyway Richard, I think we diverge from the original topic and should leave it at that.


Cheers
Allan

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Reply By: pepper2 - Wednesday, Feb 20, 2013 at 13:15

Wednesday, Feb 20, 2013 at 13:15
Thankyou to all for your informed replies,but i cant see any measurable fuel savings,maybe i am wrong.
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Follow Up By: Allan B (Member, SunCoast) - Wednesday, Feb 20, 2013 at 14:10

Wednesday, Feb 20, 2013 at 14:10
Oh, I could believe the projected fuel savings of up to 3%, and even 1 or 2% would please the Environmental agencies. They need to be seen to be 'doing something'.
Mind you, a stronger spring under the accelerator pedal may have more effect.
Dunno why they don't just fit Hiclones in the factory and save 20% !! LOL
Cheers
Allan

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Follow Up By: Kimba10 - Thursday, Feb 21, 2013 at 20:34

Thursday, Feb 21, 2013 at 20:34
And the piss arse amount of fuel you will save you will hand over more to have the starter motor replaced due to the start/stop systems on some cars, and as mentioned above when some thing bleep s its self its going to cost a fortune to repair.......Seems to be more the diesels on the 120 prados (06 to 09) with the D4D engine same as hilux where they have reduced the output. Both my 90 prados one petrol, one diesel both pumped out over 14V (14.2 for memory) current petrol prado (120 series V6) is also on 14, not modified as far as I know.............
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Follow Up By: The Bantam - Thursday, Feb 21, 2013 at 22:44

Thursday, Feb 21, 2013 at 22:44
Like all too many "environmental measures", I think if these things are studdied they will be found to be counter productive and pointless.

In short "Prius syndrome"......a car that on the surface seems to be fuel efficient and all green, warm and fizzy....but is in fact is one of the most envoronmentally damaging vehicles ever built....because of the environmemtal damage done aquiring some of the materiels, the enormous number of transport miles involved in assembling the materials, its short service life and the cost of replacing the batteries.

AND....it is less fuel efficient that some of the far more conventional, far cheaper, small cars..particularly on the highway.

It is rapidly comming to a point where, a NEW 4wd will simply not be a viable touring vehicle.

We alread have vehicles that have electrical systems so complex fitting a trailer plug to them is an engineering mission, wheel and suspension modifications are problematic because of the soon to be compulsory electronic stability controll and the current diesel engines are completely intolerant of any fuel contamination what so ever.

cheers
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Reply By: SDG - Wednesday, Feb 20, 2013 at 16:47

Wednesday, Feb 20, 2013 at 16:47
It's a wonder they haven't started incorporating solar into the paintwork on the roof. Cut down on alternator usuage again.
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Follow Up By: olcoolone - Wednesday, Feb 20, 2013 at 21:18

Wednesday, Feb 20, 2013 at 21:18
They are working on it....

http://www.abc.net.au/news/2011-06-30/researchers-develop-paint-on-solar-cells/2777532
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Reply By: Rockape - Wednesday, Feb 20, 2013 at 21:22

Wednesday, Feb 20, 2013 at 21:22
pepper2,
they do it to meet the euro emission controls. Every little bit they can ring out of an engine counts when you have to meet the controls.

Right or wrong that's the way it is.
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Follow Up By: Michael ( Moss Vale NSW) - Wednesday, Feb 20, 2013 at 22:48

Wednesday, Feb 20, 2013 at 22:48
Rockape quote; "They do it to meet the euro emission controls. Every little bit they can ring out of an engine counts when you have to meet the controls".
You are probably correct but then you hop on an Autobahn in Germany and see the smallest cars doing 200kph flat out and huge BMW, Audi and Mercs doing 250kph. Kinda defeats the purpose, with the throttle wide open and with economy tied in with emission controls. Michael
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Follow Up By: Rockape - Wednesday, Feb 20, 2013 at 23:32

Wednesday, Feb 20, 2013 at 23:32
Michael,
all it is about is the manufactures getting the vehicle to comply, after that it is not their concern.

Different I must admit when they allow high speeds on the autobarns.
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