Alternator Load Handling? (1 Viewer)

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TeCKis300

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IIRC, the OEM alternator for all 200-series is a 180A output unit.

Question for those that have lots of accessories and loads, have you found the limits of what the alternator will support? At idle? Any compromises to durability and longevity?

I'm in the planning phase to add a large Anderson plug off the rear bumper to feed an additional 40A DC-DC charger for my trailer. This would be in addition to a 20A DC-DC charger already running off the 7-pin trailer harness. This is also in addition to an 18A DC-DC charger feeding a house battery installed in the trunk of the LX570. I've got a few other aftermarket electronics doodads like cell booster and misc.

Total DC-DC charger load is nominally 78A, so I'll call it 90A with the misc. That starts getting into possibly too much for the factory alternator, considering the 200-series has plenty of power hungry electrics too. I could see this impacting alternator life.

Anyone else pushing the boundaries see any symptoms or issues as a result?
 
IIRC, the OEM alternator for all 200-series is a 180A output unit.

Question for those that have lots of accessories and loads, have you found the limits of what the alternator will support? At idle? Any compromises to durability and longevity?

I'm in the planning phase to add a large Anderson plug off the rear bumper to feed an additional 40A DC-DC charger for my trailer. This would be in addition to a 20A DC-DC charger already running off the 7-pin trailer harness. This is also in addition to an 18A DC-DC charger feeding a house battery installed in the trunk of the LX570. I've got a few other aftermarket electronics doodads like cell booster and misc.

Total DC-DC charger load is nominally 78A, so I'll call it 90A with the misc. That starts getting into possibly too much for the factory alternator, considering the 200-series has plenty of power hungry electrics too. I could see this impacting alternator life.

Anyone else pushing the boundaries see any symptoms or issues as a result?
Are you going to add any more gadgets to the rig? Have you load tested the alternator with a Carbon pile tester? I would start with load testing your alternator just to see what you are putting out. If you are with in 80% of the load rating I think you are fine but if you will be adding more to what you have now maybe look into alternator upgrades to make it simple and cut cost. Just my 2 pennies.
 
There should be spec sheets for the manufacturer/model of alternator you have that would show output vs RPM, temp limits, etc. Just need to find that but it may not be readily available. Maybe the manufacturer can provide?

Then you can measure the total of the factory loads and see where you are at.
 
I have 2x 30A units running. The line comes off of the battery and is routed through a Victron Smart Battery Protect and then to the on-board DC/DC and when attached, one in the trailer. The SBP will not allow the voltage to dip below a certain level (user set parameters). I have never seen the level drop below "normal" even when both DC/DCs are running. The SBP doesn't tell you the alternator output, but it shuts the through put down if the battery's voltage drops. Your application sounds like it is 50% more, but I think there is capacity in the stock unit for you.
 
I run a 40 amp DC to DC which charges a lithium when it's been sucked down running various gear for a few days. AT the same time I'm running lights and other aux items which is for sure drawing more than 20 amps.

No issues.

I wonder what the average life time of the alternator is in miles?

I haven't noticed many people installing higher amp alternators on the 200's.
 
Thanks for the real life examples. Had to noodle on this for awhile. I do think 90A is asking for a lot and perhaps the sane thing is to incrementally step this up as there are selectable options within my DC-DC chargers to lower output.

Charge loads can possibly be very long in duration. Exceeding the alternator output would mean the starter battery is supplementing. Perhaps can see if this is happening with a voltage output showing closer to 12.6V instead of the typical 13.6V+ with engine on. Idling and heat soak can be factors in alternator output which then means the starter battery is taking on a larger burden and possibly not charging, or worse gets discharged.

Taking a typical alternator output graphic, would mean a 180A alternator can deliver about half of that at idle. I wonder if the OEM ECU can detect alternator loads and idle up incrementally?

Given this, I've now setup the chargers to be 18A (house battery), 10A (trailer 7-pin), and 20A (trailer Anderson). That ~50A charging output, which probably really means 60A alternator load + misc in the worst case.

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So I've been watching my voltage meter closer recently.

Even with my single 18A DC-DC running, I can see about a .2V voltage drop at idle. When the car is fully warmed up, this settles to ~12.95V. Without the DC-DC load, it'll be more at ~13.2V. On the freeway with higher engine RPM, the system voltage is closer to 13.2V with all loads on.

Wondering if this minor sagging suggests that the alternator is close to its full output at idle?

Not sure if it matters, but both my starting battery and house battery were in low states of charge after using them heavy over the previous weekend. What I can't account for is the amps getting sucked down into the starting battery to recharge that. I use a Deka group 31 FLA battery which could be sucking down some serious amps too, something like 30-50 amps? AGMs are known to have even lower resistance and can suck up a good bit more amps when at low states of chargee, further loading the alternator.

Interested in any data others have to share?
 
You are probably already aware, the 200 has a temperature compensating alternator, so voltage will fluctuate due to temp as well.

In my truck, the output was ~13.9V when cold and dropped down to ~13.4V when warmed up (without any extra auxiliary loads).
 
You are probably already aware, the 200 has a temperature compensating alternator, so voltage will fluctuate due to temp as well.

In my truck, the output was ~13.9V when cold and dropped down to ~13.4V when warmed up (without any extra auxiliary loads).

Yup. My alternator resting voltage when fully warmed up after say 20 minutes of driving is closer to 13.3V without load at idle. Once I get more loads on including the 18A DC-DC, output sags 12.95V 13.1V at idle.

Wondering if there's not as much output bandwidth at idle as we all thought and I'm already consuming the margin.
 
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You are probably already aware, the 200 has a temperature compensating alternator, so voltage will fluctuate due to temp as well.

In my truck, the output was ~13.9V when cold and dropped down to ~13.4V when warmed up (without any extra auxiliary loads).
Why do they do this? Alternator health?
 
Why do they do this? Alternator health?

Battery health.

Excess current winds up boiling the electrolytes out which is why before modern compensating alternators, there was the lost art of checking and filling batts.

It's part of the reason why AGMs are futile as the charging curve is optimized for FLA batts.
 
Battery health.

Excess current winds up boiling the electrolytes out which is why before modern compensating alternators, there was the lost art of checking and filling batts.

It's part of the reason why AGMs are futile as the charging curve is optimized for FLA batts.
Good info. Thanks.
 
I’ve never noticed any charging issues on our set up; dual battery charging a redarc RedVision via anderson to my camper. Most of our accessories are lights that only see use at night so it’s not frequent enough for me to notice anything yet. I run a ARB Linx and monitor the voltage there, the house AGM starts out at 14.4 but will settle in at 13.5, starting battery stays at 13.4. I will be paying more attention to this and trans temps here soon on a trip as I’m trying to really get intimate with the noiseless happenings and behaviors of this vehicle versus listening for things falling off or breaking as my last POS vehicle was known to do.
 
I’ve never noticed any charging issues on our set up; dual battery charging a redarc RedVision via anderson to my camper. Most of our accessories are lights that only see use at night so it’s not frequent enough for me to notice anything yet. I run a ARB Linx and monitor the voltage there, the house AGM starts out at 14.4 but will settle in at 13.5, starting battery stays at 13.4. I will be paying more attention to this and trans temps here soon on a trip as I’m trying to really get intimate with the noiseless happenings and behaviors of this vehicle versus listening for things falling off or breaking as my last POS vehicle was known to do.

Good input. 13.4V on the starter battery is what I would expect it to settle at after everything warms up at steady state. That is what I'm seeing. But as I turn loads on, I'm seeing voltage sag a bit (.3V) at idle. Estimating load to be ~40A + unknown current charging starter batt. Would you know how many amps your Redarc chargers are?

I don't have a problem at the moment but I'm trying to characterize things before I put more load from my travel trailer. Drawing from 7-pin and adding an Anderson. I have two DC-DC chargers there configurable between 10A and 60A. I think I'm shooting for a middling setting of 30A to hold things reasonable. As summer is coming, would be nice to have solid power input idling during lunch stops to run the A/C in the travel trailer. The temps get up to 100*F+ here in the lowlands of the southwest before we get up into the mountains for camping.
 
Curious, as it might make a difference, where are you measuring your voltage?

What loads does your starter battery run? If it’s just a few minutes of cabin lights and starting the engine, it should top off pretty quickly from alternator charging.

Does your measured voltage go back up to ~13.4 after your aux batteries are charged? 12.9v will still provide bulk charging to your lead acid battery. But, won’t be enough to de-sulfate the plates. If the starter battery has more than usual loads on it that discharge it deeper, de-sulfating will be important to the long-term health of the battery.

I don’t have much numerical guidance to accompany that suggestion, but perhaps throw the starter battery on a charger whenever you’re near AC to get a higher voltage de-sulfate cycle in if there’s concern.
 
Good input. 13.4V on the starter battery is what I would expect it to settle at after everything warms up at steady state. That is what I'm seeing. But as I turn loads on, I'm seeing voltage sag a bit (.3V) at idle. Estimating load to be ~40A + unknown current charging starter batt. Would you know how many amps your Redarc chargers are?

I don't have a problem at the moment but I'm trying to characterize things before I put more load from my travel trailer. Drawing from 7-pin and adding an Anderson. I have two DC-DC chargers there configurable between 10A and 60A. I think I'm shooting for a middling setting of 30A to hold things reasonable. As summer is coming, would be nice to have solid power input idling during lunch stops to run the A/C in the travel trailer. The temps get up to 100*F+ here in the lowlands of the southwest before we get up into the mountains for camping.
It’s hard to say exactly what the redarc in the camper is pulling for 2 reasons, 1. The RedVision display would show this but it’s in the camper, Bluetooth to the phone app is beyond range inside the cruiser and 2 the redarc prioritizes green so it takes from the solar as much as possible and I have 200 watts on the roof. I can say that the redarc BMS is maxed at 32.4 amps.
 
Curious, as it might make a difference, where are you measuring your voltage?

What loads does your starter battery run? If it’s just a few minutes of cabin lights and starting the engine, it should top off pretty quickly from alternator charging.

Does your measured voltage go back up to ~13.4 after your aux batteries are charged? 12.9v will still provide bulk charging to your lead acid battery. But, won’t be enough to de-sulfate the plates. If the starter battery has more than usual loads on it that discharge it deeper, de-sulfating will be important to the long-term health of the battery.

I don’t have much numerical guidance to accompany that suggestion, but perhaps throw the starter battery on a charger whenever you’re near AC to get a higher voltage de-sulfate cycle in if there’s concern.

Salient question and I was originally referencing my DC-DC Victron charger via BT that's located behind 6 ft of 4-gauge to the trunk area. Realized it was better to reference my SwitchPros via BT that is 1ft of wire from the battery. That doesn't show as much sag as it reads 13.1V with loads on at idle (vs12.95V). And 13.3V at freeway RPMs with loads on.

Batts are both fully charged and it will still sag about the same.

I'll get the Anderson and additional loads on for a trip this summer and see how things go.
 
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FWIW, the 4Runner settles at 13.3-13.4v (measured at the front cig socket) with its temperature compensating alternator. So it would seem that that’s enough voltage to do desulfating.
 
TeCKis300,

Just s FYI, I've had good luck installing this companies alternators in our fire vehicles, which are power hogs. They make good products, build and ship fast, and are helpful on the phone.
They have a number of amperage options for the 200 series.


Screenshot_20230604_070046_Brave.jpg

Screenshot_20230604_070100_Brave.jpg


Note: I am not an employee or affiliate of this company. Just my experiences dealing with them.
 
TeCKis300,

Just s FYI, I've had good luck installing this companies alternators in our fire vehicles, which are power hogs. They make good products, build and ship fast, and are helpful on the phone.
They have a number of amperage options for the 200 series.


View attachment 3340008
View attachment 3340009

Note: I am not an employee or affiliate of this company. Just my experiences dealing with them.

Nice, there's a whole slew of options out there I wasn't aware of. Thank you!
 

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