Alternator output at idle? (2 Viewers)

[VooDoo2]

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

 

[KJun]

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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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.

 

[VooDoo2]

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.

Working awesome. I supply lithiums for this application and have 1000's out there





You see me in the background a few times

 

[FrazzledHunter]

Working awesome. I supply lithiums for this application and have 1000's out there





You see me in the background a few times

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?

 

[TheGrrrrr]

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?

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.

 

[FrazzledHunter]

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.

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.

 

[KJun]

Working awesome. I supply lithiums for this application and have 1000's out there

You see me in the background a few times

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.

 

[eatSleepWoof]

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?

 

[BlackMammoth]

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.

 

[TeCKis300]

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.

 

[eatSleepWoof]

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.

 

[BlackMammoth]

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.

 

[FrazzledHunter]

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.

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.

 

[TheIcemanCometh]

I've run a Victron 12|24-15 Orion-Tr Smart DC-DC Charger Isolated

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 ?

 

[FrazzledHunter]

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 ?

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.