Alternator output at idle?

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I charge Lithium batteries direct @ 200a. If you have lead acids its completely pointless as the batteries can only absorb 20-30a anyway.

These are sealed, Watercooled, Brushless and 200 amp outputs

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KJun said:
Reviving an old thread but just curious if you meant that you're charging a LifePO4 starter battery directly from the alternator? If that's the case very curious how that's working out.
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Working awesome. I supply lithiums for this application and have 1000's out there





You see me in the background a few times
 
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VooDoo2 said:
Working awesome. I supply lithiums for this application and have 1000's out there





You see me in the background a few times
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The "Charging DCS lithium batteries directly off 4WD alternators" video states @ 2:30 that the LC 200's alternator is rated at 150A. I thought it was 180A. Mistake?
 
FrazzledHunter said:
The "Charging DCS lithium batteries directly off 4WD alternators" video states @ 2:30 that the LC 200's alternator is rated at 150A. I thought it was 180A. Mistake?
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Maybe a difference between the diesel and petrol engines? I have a vague memory of it being the 5.7 petrol in the US is 180A and the 4.5L Diesel elsewhere is 150A. Someone more knowledgeable should feel free to correct me.
 
TheGrrrrr said:
Maybe a difference between the diesel and petrol engines? I have a vague memory of it being the 5.7 petrol in the US is 180A and the 4.5L Diesel elsewhere is 150A. Someone more knowledgeable should feel free to correct me.
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I keep forgetting about the diesel option being available elsewhere. Thanks!

I was also wondering what the value for "maximum" and "idle" rpm's that were referenced in the video.
 
VooDoo2 said:
Working awesome. I supply lithiums for this application and have 1000's out there

You see me in the background a few times
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Awesome. That's been my experience as well for the past few years after replacing my starter with a cheap LifePO4 I found second hand on Craigslist. No issues at all for the past few years even with the last two years in the cold winter of New England. I do have some concerns around the make of LifePO4 that I have (Valence 27) not having an inbuilt BMS could be an issue or shorten battery life in the long term. For an under hood solution I was considering putting a Redarc 50amp BCDC between the starter and alternator which would give me a Lithium charging profile as well as low temp cutoff. But that would effectively limit my alternators output to 50amps and concerned if that could drain my battery under heavy load where you need the full output of the alternator.
 
Bumping up an old thread.

Has anyone confirmed OEM alternator's output at idle lately? It sounds like folks are using 50amp DC/DC chargers with good success; can anyone chime in with more feedback?
 
I charge 200ah of Lithium using a DC-DC charger and it pushes 50amps through the battery monitor shunt even when I know the Land Cruiser start battery has been significantly discharged. I suspect the alternator is capable of putting out at least 65+ amps at idle since it has to provide for the start battery + the vehicle loads (engine / lights / etc) + the DC-DC charger which is probably drawing 56 amps give or take an amp.
 
I'm sure the alternator will support some good load at idle. Question may be more the longevity of the alternator cranking that many amps at idle?

I'd watch the total added output. DC-DC chargers, trailers, upgraded starter batts (esp AGM), are going to add wear and tear.

Significant loads are going to add significant heat especially at idle. Probably more a concern in the summer. I haven't put much time into looking, but from @FrazzledHunter s alternator upgrade thread , might be worthwhile finding a slight 2.25" overdrive pulley, partially to help the alternator make more power, but moreso to increase cooling.
 
Good data points and ideas about upgrade, thanks to both!

On my end I'm thinking of playing it safe and keeping the DC/DC charger to no more than 40a, which should be sufficient for my needs in any case.
 
Stock alternators are (relatively) cheap. I live in the desert and haven't fried the stock unit in the last few years.

When I was cruising on a sailboat for 3 years I had a large frame Electrodyne alternator... but I used to push 100s of amps for hours.
 
eatSleepWoof said:
Good data points and ideas about upgrade, thanks to both!

On my end I'm thinking of playing it safe and keeping the DC/DC charger to no more than 40a, which should be sufficient for my needs in any case.
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You're probably OK at 40A load on the alternator. I've run a Victron 12|24-15 Orion-Tr Smart DC-DC Charger Isolated to charge a Goal Zero Yeti 1500X for about 3 years with no problems. My data is as follows: peak output from the Orion measured 23.25A @ 16.53V with a measured 40.08A @ 13.21V on its input. It didn't draw that much all the time, just when charging a very discharged 1500X.

EDIT: be careful what you call "idle" RPM.
I noted 3 idle RPM's:
  • 1000-1200 RPM starting cold in park.
  • 700 RPM warmed up in park.
  • 550 RPM warmed up in drive foot on brake.
That last value caught the vendor of my upgraded alternator by surprise. It was the last value that prompted concern that the vendor of my upgraded alternator recommended reducing the size of the alternator pulley to 2" (from 2.5" which is OEM stock) to give me 200A @ 550 RPM.
 
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TheIcemanCometh said:
Why are you running an Isolated charger? Are you not using the chassis as a ground for both the starter battery and the secondary battery ?
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The Yeti Goal Zero is a portable stand-alone power station. It is not a raw lithium battery whose neg/- would be connected to a chassis as in a travel trailer or sprinter-van type of setup. Since there is no connection to the chassis with this unit, nor is one possible, without an isolated ground I don't see what the reference potential from + to - would be. So I opted for a sure-thing with an isolated ground.

On the other side of the input is a MPPT controller so the Victron charger* is masquerading as a solar panel. Their AC chargers do the same thing. The trick to charging this thing is understanding that it wants 14+ volts before it will accept a charge, hence the 12|24-15 instead of a 12|12-30.

There are also 2 different voltages involved 12V input and 24V output - not that this by itself necessitates an isolated ground AFAIK.

Charging is accomplished by an Anderson Powerpole PP-45 connector or an 8mm connector.
Yeti 1500X - https://www.goalzero.com/products/goal-zero-yeti-1500x-portable-power-station

*EDIT: forgot to mention that the Victron unit is set up in power supply mode that supplies constant power and not battery charger mode which follows a battery charging profile.
 
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Sorry for the thread revival but it’s on topic,

I just got a 2014 LX with 97k. How long do the stock alternators typically last?

I plan on running some pretty big RF transmitters. I have ran DC Power XP270( 200 idle) alternator for 15 years on my Super Duty 6.0 and was planning on getting one for my LX. I also like that they use the same size pulley as stock. Has anyone had experience with these on LC/LX?
 
FrazzledHunter said:
My data is as follows: peak output from the Orion measured 23.25A @ 16.53V with a measured 40.08A @ 13.21V on its input. It didn't draw that much all the time, just when charging a very discharged 1500X.
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Do we have any more data now? Looking to pick up a DC-DC charger for my power station. Lots of options on the market now, even upwards to 1000W from the alternator. (That's 80A !!?) I don't think I'll realistically need 1kw of DC-DC charging. But since cost between the 500W~100W chargers are not that dramatic. Wondering if I could pick up a more powerful one to "leave room to grow" in the future? Or would it be a total waste of money.

TheGrrrrr said:
Seem if that were drawing even 2/3 of the fused total or 80A, tacking another 50A on would be a bit much. Unsure if the RedArc has been drawing a full 24A any time that I’ve used the compressor, but I suspect it has. Definitely something I hadn’t thought enough about. Now I’m even more interested in the 270A alternator.
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My rig is 250k with the factory alternator. Has there been more data on the 270A alternator?
 
Musubi said:
Do we have any more data now? Looking to pick up a DC-DC charger for my power station. Lots of options on the market now, even upwards to 1000W from the alternator. (That's 80A !!?) I don't think I'll realistically need 1kw of DC-DC charging. But since cost between the 500W~100W chargers are not that dramatic. Wondering if I could pick up a more powerful one to "leave room to grow" in the future? Or would it be a total waste of money.


My rig is 250k with the factory alternator. Has there been more data on the 270A alternator?
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I've been using a 40a DC/DC charger for the past 2 summers. Works great, and I find it to be a nice middle ground between output and not over-stressing the alternator.
 
Musubi said:
Do we have any more data now? Looking to pick up a DC-DC charger for my power station. Lots of options on the market now, even upwards to 1000W from the alternator. (That's 80A !!?) I don't think I'll realistically need 1kw of DC-DC charging. But since cost between the 500W~100W chargers are not that dramatic. Wondering if I could pick up a more powerful one to "leave room to grow" in the future? Or would it be a total waste of money.


My rig is 250k with the factory alternator. Has there been more data on the 270A alternator?
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Remind me which power station you have?

The charging data for the Orion has been fairly constant. There's nothing really new to report. My power station is a Goal Zero Yeti 1500x. DC charging capability on my station is max 600W or 50A at 12v. My Orion is capable of the numbers I reported - 360-400W. I would have gone higher power with a Victron unit but I couldn't find one bigger at the time I started all this. The wiring I currently have, an Anderson SB-50 6GA wire, located at the driver and passenger foot-well could easily support 50A. Goal Zero's car charger, released a year after I got t he Orion, was capable of 600W but was problematic for other reasons. So I stuck with the Orion. Depending on your power station you'll need to be aware of charging voltages. My Goal Zero requires >14V to charge. Victron has a 50A model capable of 17V out now and I would probably use that if I were starting out today.

But it's all different now. I think EcoFlow is the new big man on campus with something like 800W charging capability plus1) the ability to limit charging power to what your alternator can handle and 2) the ability to back-charge the starter battery from the power station.

Re: a 270A alternator. Why not go with the 390A (which is what I installed)? You'll need to do the same up-wiring with a 270A as a 390A if you actually intend to draw above what's OEM so there's no real saving with a 270A unit, IMHO.:cool:

To get real power at idle order the alternator with a smaller pully and put in a shorter serpentine. The serpentine has to be removed to install the alternator anyway, Again, no real saving in keeping the old serpentine. This combo has served me very very well. I can simultaneously run the LC, charge the Yeti at 400w and the Lithiums in the trailer at 600W. I haven't even come close to maxing out that alternator. Yet. ;)

REF: Alternator upgrade - done! - https://forum.ih8mud.com/threads/alternator-upgrade-done.1329033/post-15291106
 
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FrazzledHunter said:
Remind me which power station you have?
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I had an Ecoflow delta mini that could only take 300W of DC input. But I'm picking up a larger unit during black friday, mostly likely the Pecron f3000 which can take 1600W of DC input (way over kill, but cool that I can combine alternator and solar simultaneously)

FrazzledHunter said:
Re: a 270A alternator. Why not go with the 390A (which is what I installed)? You'll need to do the same up-wiring with a 270A as a 390A if you actually intend to draw above what's OEM so there's no real saving with a 270A unit, IMHO.:cool:

To get real power at idle order the alternator with a smaller pully and put in a shorter serpentine. The serpentine has to be removed to install the alternator anyway, Again, no real saving in keeping the old serpentine. This combo has served me very very well. I can simultaneously run the LC, charge the Yeti at 400w and the Lithiums in the trailer at 600W. I haven't even come close to maxing out that alternator. Yet.
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huh didn't even know there is a 390A option. Definitely will keep that in mind for the future. I think for now I'll run my stock alternator at 40A ish until replacement.
 
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