smart alternator override

[Jasonmc73]

The method I use has been mentioned a lot on the forum. Just leave the cabin fan turned on all the time. Easy. The aircon doesn't need to be turned on and the fan can be on low, so it's barely noticeable. So no cutting wires or modification to factory systems.

Try this. It's quick, easy, free and reversible.

My fan runs always as well, the system sees a load & raises voltage granted.

Triton dumb alternator generally runs around at 14.4 volts, Tritons battery last's quite a while.

Pajero sitting for 2 weeks, start it, lights on at idle under 14 volts, few revs 14.2 tops, battery certainly no where near charged.

Batteries don't last to well in many peoples Pajero's for some reason, maybe its hot under there, but aren't all cars, maybe ECU's vary?

I'm not a real fan of Smart alternator's & there charging profiles, which i don't for a second think i completely understand myself, i would rather burn the fuel & have a really dumb alternator.

I can tell you though, C-Tek 15amp charger fits a fair trickle charge often at 14.6 volts, length of time after pushing in a bulk charge, often when i put it on the car.

Same goes for Wives Mazda 3, occasionally give it a charge when charging AGM's in camper which i do every 4- 6 weeksish.

Not hard.

I do know from experience with lots of new & used machines with batteries, either shake the shit out of them/ vibration, bang bang bang, keep them under charged is best way to make sure they die fast.

Keep them full up, is my opinion, but i'm not an expert just what i do, i think Smart alternators have other motives at hand in line with being a battery charger.

[Shauns]

Hi.
Thanks for all the tips.
my fan is on 100% of the time.
when cold I can hit 14.3v.
when warm (normal) it's sits on 13.9_14.0.
when hot (hot day or working hard) drops to 13.7.
I want 14.2 to 14.6 all the time.

today I disconnected the current sensor on the neg terminal it made no difference stayed on 13.8_14.0.
This is too low for the agg power AGM I have under the bonnet.
I don't want to run a dcdc charger under the bonnet, I like the isolater, on my old NT I ran the same isolater under the hood and a dcdc to the rear lithium.
The system with the dcdc charger to the rear lithium works well if the voltage is over 14.2.
given the voltage did not change by disconnecting the current sensor, the controlling voltage must be by temp or the alternator regulator.

[Dicko1]

Sorry Dicko, but this is simply wrong. I believe you're thinking of charging lead acid batteries in series, not parallel. I expect the systems you maintained during your career were banks of batteries in series, to create higher voltages - probably 48V battery banks, floating at about 55V, possibly boosting higher. If this thread was talking series charging, I would agree. For parallel charging this is simply wrong.

Lead acid batteries are incredibly simple to charge - they take the charge current that they want, based on available voltage, state of charge, and temperature. When charged in parallel, with a constant voltage float charger with the correct voltage, each battery will take care of itself - as the state of charge increases the battery draws less current. The battery is controlling this behaviour, not the charger. But this isn't the fastest way to charge them.

If you want to add a multi-stage charger into the equation, which changes its output voltage based on charging current, then things change, but not as you have stated.

A multi-stage charger uses a higher voltage in its bulk charging phase, while the battery is in a lower state of charge, which results in a higher charge current and faster charge. As the state of charge rises, the charger senses the change in terminal voltage, and will then hold the voltage at a set level for the "absorption" phase. During this phase, the charger monitors the current, which will ramp down as the battery continues to increase its state of charge. During this phase, it is not the charger that is reducing the current, but the battery controlling how much current it will take - based on applied voltage, and battery temperature. Once current drops below whatever point set by the charger designer, the battery voltage will drop to its float charging voltage, and the battery will continue to draw whatever current it wants.

With two batteries in parallel at different states of charge, different things will happen.

In the bulk charging phase, the battery with the higher state of charge will reach the "switching threshold" sooner, causing the charger to detect this threshold voltage, and switch to absorption mode.

In absorption mode, the battery with the higher state of charge will continue to charge quickly, but the charger is now monitoring current draw. The battery with the lower state of charge will continue to draw current as it continues to charge, but the battery that started with a higher charge will begin to overcharge - overheat, off gas, suffer.

Only once the battery with the lower charge drops its charge current below whatever threshold will the charger change to its float mode, and slowly bring the battery to 100% - but by then, the other battery has been overcharged.

You are right. I found this on another forum and just thought I would post it up to see who would take the bait. Not stirring or being a smartarse but it just shows that there is a lot of misinformation. I knew someone would chip in. However I would not charge two different types of batteries. Lets face it ...99% of the time they would be in parallel and the smart charger (which the majority of people use anyways) would then affect the batteries in the way you stated. Like the old saying about a chain and its weakest link. Parallel batteries are only as good as the weakest one. I haven't used a constant volt charger in decades. We use to use very large inverters to drop solar intake down to about 52 volts. However when ever batteries needed changing we changed the entire bank with the same size, brand and a close manufacture date.

[Dicko1]

Hi.
Thanks for all the tips.
my fan is on 100% of the time.
when cold I can hit 14.3v.
when warm (normal) it's sits on 13.9_14.0.
when hot (hot day or working hard) drops to 13.7.
I want 14.2 to 14.6 all the time.

today I disconnected the current sensor on the neg terminal it made no difference stayed on 13.8_14.0.
This is too low for the agg power AGM I have under the bonnet.
I don't want to run a dcdc charger under the bonnet, I like the isolater, on my old NT I ran the same isolater under the hood and a dcdc to the rear lithium.
The system with the dcdc charger to the rear lithium works well if the voltage is over 14.2.
given the voltage did not change by disconnecting the current sensor, the controlling voltage must be by temp or the alternator regulator.

My voltage on my NW is often below 14 volts yet the dcdc works fine.Not too often its at 14.2 even with air con going most of the time.

[nj swb]

when cold I can hit 14.3v.
when warm (normal) it's sits on 13.9_14.0.
when hot (hot day or working hard) drops to 13.7.
I want 14.2 to 14.6 all the time.

Your factory charging system is doing what it's supposed to do, recharging your starting battery and trying not to overcharge it when things are hot.

Yes, 13.7V looks low, but this is when things are hot - 13.7V can still overcharge a hot battery.

But I do agree that it's frustrating to see your alternator voltage at 13.7V when you know you want to pump charge into your auxiliary battery - so I understand your desire to see 14.x volts all the time.

Remember that 14+ V all the time will be overcharging your starting battery, leading to a reduced service life. Just one more trade-off we make playing this game.

[Shauns]

Thanks for the replies.
I currently get 2 years out of a battery in the NX or the old NT (sold).
I purchased a starter and deep cycle in March 19.
I have replaced the deep cycle this weekend, the starter is on the way out a 775cca that only puts out 600cca now and holds 11.9v in the morning.
my old Torrana had a dumb alternator that put out 14.4 volts, I had a battery last over 4 years.
Previous deep cycle batteries have just been the century lead acid, this time I'm trying an agg power AGM, (similar to an optima) it can take up to 15v cycling, I would happy to put 2 of these in.
I have even resorted to a 100w solar panel for the aux battery to try and keep the charge.

can a person that does a chip tune, alter the voltage ?
can we put a different regulator on the alternator.

What I have now with below 14v is not good enough and is leading to batteries only lasting 2 years, I suspect through lach of charge.
I run a fridge 50% of the time set to medium for voltage cutout, so effectively get only 300 cycles out of the aux battery.

if the system is working as designed, the design is faulty.

[Jasonmc73]

if the system is working as designed, the design is faulty.

Like most smart alternators, the reason they are so clever is in the eye of the designers

A bit like beauty i suppose

[nj swb]

if the system is working as designed, the design is faulty.

I don't disagree with this. Starting batteries should last longer than 2 years.

But I disagree that the problem is undercharging. I believe the problem is overcharging.

Go back and have another look at the engine bay of your old Torana. I expect it had much more space, the poor aerodynamics forced much more air through the engine bay, and the battery remained much cooler.

Your Pajero has

• much more stuff under the bonnet, restricting space available for air flow in the engine bay,
• better aerodynamics to divert air around the vehicle, reducing air flow attempting to enter the engine bay,
• more radiators / heat exchangers at the front of the engine bay to restrict whatever flow tries to enter the engine bay, and
• a more powerful engine pumping more heat into an engine bay with less ventilation.

Your Pajero's battery is failing early because it lives hotter than your Torana's battery did, and the lower charging voltages are still too high.

Raising the charging voltage will allow your auxiliary battery to charge faster. But it will cause your starting battery to fail earlier.

Every engineering decision is a trade-off. Mitsubishi's engineers made their decisions, and accepted the outcomes. Now you get to make yours.

[Jasonmc73]

I don't disagree with this. Starting batteries should last longer than 2 years.

But I disagree that the problem is undercharging. I believe the problem is overcharging.



Every engineering decision is a trade-off. Mitsubishi's engineers made their decisions, and accepted the outcomes. Now you get to make yours.

Most times i've checked Triton dumb alternator voltage its above 14 volts, but i've always known Triton's are cool after all
I don't monitor its voltage just an observation when i was monitoring for a project.

My Wives Mazda 3, clever alternator as well, clever battery worth heaps, don't last real long though, well 3 years better than 2 years i guess.

[Dicko1]

Thanks for the replies.
I currently get 2 years out of a battery in the NX or the old NT (sold).
I purchased a starter and deep cycle in March 19.
I have replaced the deep cycle this weekend, the starter is on the way out a 775cca that only puts out 600cca now and holds 11.9v in the morning.
my old Torrana had a dumb alternator that put out 14.4 volts, I had a battery last over 4 years.
Previous deep cycle batteries have just been the century lead acid, this time I'm trying an agg power AGM, (similar to an optima) it can take up to 15v cycling, I would happy to put 2 of these in.
I have even resorted to a 100w solar panel for the aux battery to try and keep the charge.

can a person that does a chip tune, alter the voltage ?
can we put a different regulator on the alternator.

What I have now with below 14v is not good enough and is leading to batteries only lasting 2 years, I suspect through lach of charge.
I run a fridge 50% of the time set to medium for voltage cutout, so effectively get only 300 cycles out of the aux battery.

if the system is working as designed, the design is faulty.

My battery in the NW is now 40 months old. Century 4wd off road model. I have a decent solar panel on the roof that can produced 8 amps. I can switch the output of the solar to either feed the start battery or the aux lithium battery. Both have their own MPPT regulator to match their characteristics (lithium-wet cell). Stop start suburban traffic , like heat, kills batteries quicker than highway travels. As you already have the solar why not feed this to the starter battery (leave connected all the time) and this will also charge the aux as well. Cant hurt to try.

[Fritterbug]

My NW is now nearly 8 years old. This is its third battery. I have never had a good run with them. Whenever I have left it sitting for a few days the car is sluggish to start.
Currently it has a 90ah AGM for a starting battery and the problem persists.
The original battery I persevered with for 3 years or so. Then I bought a Century Overland N70 which I guess did 3 years and the current AGM has been maybe 2 years but not sure

I connect the car to a CTEK charger in the carport every so often (sometimes weekly, sometimes monthly) to bring it up to speed but once it has been driven a few times the battery is low again.
I have a bluetooth voltage monitor on it that reports to my phone and it is easy to see over time that the starting battery never gets even close to a full charge from the alternator.
I have measured the voltages when driving and you can see the charge rate goes up and down with the smart alternator.

My air-conditioner is operating 99.9% of the time and has no effect on making the charge voltage stable at 14.4v or anything near to that.

I would love to disable the smart function of the alternator to see if this helps in any way.
I understand that there are reasons for having a smart alternator but my understanding is it is mainly fuel consumption reasons. I would much prefer to spend i little bit extra at the pump and have my battery fully charged (assuming the variable voltage is the reason for the batteries not charging properly).

I run another 110 ah AGM as a second battery through a CTEK 25 amp DC-DC that gets removed from the car when not in use.

Every year or so I look into bypassing the alternator smart function but so far have never tried anything and never come across any info from anyone who has.

So this is nothing that hasn't been said above but I'm just adding my 2c

[dhula]

I'm no expert in this and have only looked at the online manuals, not actually looked at the Paj.

It looks like the difference between the smart alt and the dumb alt on the deso Paj's is 2 wires that come out of the 4pin plug on the back of the alt.
These wires go to the engine ecu first by the looks of it and then to the battery current sensor.
The wires in question are the very outside (#1 and #4) on the plug and are coloured Yellow-black and Black-Red.

I wonder if it could be as simple as disconnecting one or the other or maybe both and you'd get a constant 14+ volts.

[erad]

I am no auto electrician, but, like all things on these modern cars, there was a purpose behind all the 'innovations', including smart alternators. The designers are not going to put in stuff which costs more money if there is no logical reason for doing so. Unless you have experience which is superior to the original designers, I would be reluctant to change the original design. For example, it you disconnect the return current sensor on the battery earth terminal, I expect that you would be getting 16 to 18 volts (or whatever the alternator could put out into yuor 12 V system, with the attendant risk of blowing various component. The cheapest of these would be light bulbs, but ECu's are also connected and they are not cheap.

[dhula]

I agree that the engineers/designers did what they did when designing the Paj and all it's gizmo's and systems but I also agree that if the current design is not satisfying the need of the end user then that design needs tweeking or changing somehow to meet the needs of said user.
It's either change the design to meet the need or buy something else. If wanting to either keep the Paj or keep in a car that is less than about 10 years old then it seams the design change is pretty much the only option.

So far the batteries in our Paj are performing as expected. The start batt is on it's 4th year of service and doesn't look like slowing down yet, the aux battery is into it's 3rd year of service and still gives almost 40hrs of life before reaching 50%dod so I have no need or desire to change anything in our Paj yet. I'm about to wire up the Paj to be able to charge a 300ah bank in our camper while on the move so things may change but we'll see.

To put wood on the fire regards the battery life and performance verses smart-v-dumb alternator discussion.
In one of our previous 4wds, a 95s Prado with the awesomely powerful 1KZ-TE powerplant, the OEM battery lasted somewhere around the 7 year mark. It was still starting the Prado fine when changed and still showed satisfactory results when tested but we took the option of changing it as a preventative measure due to planning a remote trip at that time. We changed it to a Delkor Calcium start battery that was still in the Prado when we sold it about 3-4 years later. We also had fitted a ~105ah deep cycle battery not long after we brought the car, a Delkor Calcium that was separated from the start battery by a Pirhana isolater, that was still in the Prado at time of sale making the DC battery about 10-11 years old and was still giving close to 50hrs before reaching 50%dod. These batteries never saw a 240v changer or a solar panel in their life while we had them and were only ever charged by the Prado. They were dropped into the battery cradles at the Delkor sellers shop and that was it. I will add that both the batteries were not maintenance free type and I checked/maintained water levels and overall cleanliness roughly every 2-3 months which will have definitely helped with the long life.

The Prado being an early 2000's had a dumb alternator that put out somewhere around the 14.4v mark pretty much constantly. I can't remember how many amps it was rated to but it was likely around the 100 mark I think. Given the dumb alt+14.4v+how long the batteries lasted for us, I'd say it was a pretty good way of doing things and was simple in design.
The Paj on the other hand I can't say either way really. We've got ours doing what we need for the moment, this might change once we set up for the camper but only time will tell. Having read many stories and posts regarding the Paj smart alternator I can only take away that in some circumstances the design and way it works proves to be problematic for some.

Can the fix be as simple as disconnecting a couple of wires on the back of the alternator or maybe even simpler (but slightly more expensive) and just change the alternator to a dumb one and rewire were needed. I don't know but either way might be a suitable solution.
According to the service specs in the online manuals the alternator is able to put out up to 15.4v so I'd assume all the electronic gizmos can handle up to at least that much and still be within safety margins that were designed/engineered by someone smarter than me at Mitsubishi.

[oldmate]

Similar to the smart alternator on the Navara D40 we had, it used to charge at 12.5v with temporary excursions into the 13/14s.
I unplugged the harness at the hall effect sensor on the negative lead like a couple of other guys had done and had the next 7 years of charging with no dramas. Charge voltage constantly between 13.8 and 14.4v, the original start battery lasted 5 years and the Redarc SBI12 that was already 5 or 6 years old when I installed it worked like a dream charging the Aux in the tray until I sold it last year.
IMHO smart alternators aren't that smart and are only there to squeeze that last little bit of emission controls blood out of the stone for compliance testing. They need to be made a lot smarter.