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Discussion Starter · #23 · (Edited)
I was thinking is was new, nope apparently boater's have been doing this for years :)

It seems they attach it to the case mount bolt, I was wondering if the positive terminal or another spot would give a more accurate reading?

I wonder if any B2B's use a temp sensor on the alternator to control it's own output?
So Sterling has an Alt to battery unit that turn off when alt is above 90°c
 

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I was thinking is was new, nope apparently boater's have been doing this for years :)

It seems they attach it to the case mount bolt, I was wonder if the positive terminal would give a more accurate reading?

I wonder if any B2B's use a temp sensor on the alternator to control it's own output?
Sounds clever! I wonder how boats keep their alternators cool. There's no airflow, right? Or do they use big fans in their engine compartments?

As someone who used to overclock their computer processors, I wonder how effective something like active cooling could be on an alternator (i.e. a powerful fan on it), maybe with a big heatsink too, to draw away heat as it's being actively cooled.

Re: B2B chargers and temp sensor: Maybe an ingenious person could attach a sensor to the alternator and read it with a Raspberry Pi or Arduino.

And if the reading exceeds a threshold, trip a relay or something that will switch those chargers that have a 50% power setting (like some Renogys do) to use the lower setting. Or perhaps turn the B2B off altogether.
 

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Discussion Starter · #25 ·
From reading IIRC boat's would use something like a Balmar regulator on the alternator to deal with alternator overheating.

Renogy has a battery temp sensor for the b2b that controls the voltage, not sure if putting the sensor on the alternator would achieve the same results.

To me, it seems like having a b2b that monitors alternator temperature to regulate current output would be idea.

alternator cooling isn't new either apparently
Gesture Font Cylinder Auto part Automotive design
 
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Renogy has a battery temp sensor for the b2b that controls the voltage, not sure if putting the sensor on the alternator would achieve the same results.
It's common for chargers (solar, shorepower, alternator) to use battery temp sensors for voltage temperature compensation with lead-acid batteries (not applicable to lithium). Below 25*C, it increases the target charge voltage for 12V systems by 12mV per *C, and decreases voltage by the same amount above 25*C. So at 100*C, it would reduce voltage by 0.9V (= 0.012V * 75). I'm not sure if or how that affects amps, but certainly not enough.
 

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The subject of "overloading the alternator" seems to come up all the time in the forum but I cant recall anyone reporting actually burning out an alternator and seems like nearly every camper has a high draw B2B or straight unfettered alternator charging of camper battery so I wonder if its really a concern? A dead starter battery should also draw a large current. The amp numbers are interesting, amazing how little effort went into making the electrical system efficient on these vans. I wonder how much fuel (if any) is wasted by using in-efficent high draw electrical components.
 

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The subject of "overloading the alternator" seems to come up all the time in the forum but I cant recall anyone reporting actually burning out an alternator and seems like nearly every camper has a high draw B2B or straight unfettered alternator charging of camper battery so I wonder if its really a concern? A dead starter battery should also draw a large current. The amp numbers are interesting, amazing how little effort went into making the electrical system efficient on these vans. I wonder how much fuel (if any) is wasted by using in-efficent high draw electrical components.
 

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I read in a few places that this famous video has been debunked. I think that is why the comments have been turned off.
I believe all Victron videos, including prior videos have the comments turned off. What parts of this video have been "debunked", specifically?
 

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I watched that video. There is no battery to battery charger. They're driving to lithium directly from the alternator which in my opinion is a contrived and unrealistic test scenario. Yeah sure maybe 10 or 15 years ago people were selling lithiums as lead acid replacements and this video might apply. But who would need a 300 amp hour lithium as a car battery replacement? And under what circumstances would it be depleted 50%?

IMO This video is nothing more than marketing for the Balmar alternator.
 

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Discussion Starter · #32 ·
2 things
Isn't the alternator rpm's kind of low?
Why would my alternator burn up with only 65 amps?
 

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I watched that video. There is no battery to battery charger. They're driving to lithium directly from the alternator which in my opinion is a contrived and unrealistic test scenario. Yeah sure maybe 10 or 15 years ago people were selling lithiums as lead acid replacements and this video might apply. But who would need a 300 amp hour lithium as a car battery replacement? And under what circumstances would it be depleted 50%?

IMO This video is nothing more than marketing for the Balmar alternator.
I believe the 300ah represented a coach battery rather than a starting battery.
 

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I believe the 300ah represented a coach battery rather than a starting battery.
Of course. Still, why would one bolt the coach battery directly to the alternator? That is so 2004 when LiFePO4 replacements for starter batteries first came out.

A properly sized b2b charger is the right solution for big coach batteries. All the video shows is that one could easily overload a small alternator with a huge battery.

Maybe I'm missing something here. Are people burning out their alternators a lot? Doesn't seem so based on the lack of postings and the number of Vans running around with big house batteries.
 

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Of course. Still, why would one bolt the coach battery directly to the alternator? That is so 2004 when LiFePO4 replacements for starter batteries first came out.

A properly sized b2b charger is the right solution for big coach batteries. All the video shows is that one could easily overload a small alternator with a huge battery.

Maybe I'm missing something here. Are people burning out their alternators a lot? Doesn't seem so based on the lack of postings and the number of Vans running around with big house batteries.
Balmar is used extensively in marine applications and second alternator scenarios. That second alternator does not go thru the starter battery to charge other battery banks. Victron was originally used in the shipping industry.
 

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Of course. Still, why would one bolt the coach battery directly to the alternator? That is so 2004 when LiFePO4 replacements for starter batteries first came out.

A properly sized b2b charger is the right solution for big coach batteries. All the video shows is that one could easily overload a small alternator with a huge battery.

Maybe I'm missing something here. Are people burning out their alternators a lot? Doesn't seem so based on the lack of postings and the number of Vans running around with big house batteries.
While I agree that it is a fair bit of marketing, you would be surprised at how many people still promote the idea of just hooking up a large battery bank, regardless of SOC, directly to the alternator on forums, IG and youtube.

I still commonly get calls from people who have had their fairly reputable van builders do this as well and it is a delicate political dance to move them over to a BTB setup.

As far as Balmer - they are very reputable and it is a step in the right direction, but I am not 100% in agreement that their controller is correct for charging LiFe either. It does not have as much control of amps as it ideally should IMHO.
 
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While I agree that it is a fair bit of marketing, you would be surprised at how many people still promote the idea of just hooking up a large battery bank, regardless of SOC, directly to the alternator on forums, IG and youtube.

I still commonly get calls from people who have had their fairly reputable van builders do this as well and it is a delicate political dance to move them over to a BTB setup.

As far as Balmer - they are very reputable and it is a step in the right direction, but I am not 100% in agreement that their controller is correct for charging LiFe either. It does not have as much control of amps as it ideally should IMHO.
I think along the same lines as you with this @HarryN. In 2018 I attempted to understand (or get the spec) on the PM Alternator regulation (note Computer controlled by the onboard PM computer as far as I know). Never have seen this info I am looking for. My 2018 PM alternator was the 180amp & I ordered the 220amp for our 2021.

That being said, I note “Factory Setup” has;
1) 70amp upfitter fuse
2) Spare slot for a “mega” fuse or in @Sather case and others seemingly a 250amp factory installed fuse in the spare location

My point is Ram must have taken these upfitter loads into consideration. IIRC the 220amp alternator is supplied in “The Ambulance Package”. I would think they (Ram) has designed some sort of control (& spec’d limits) around their alternators & regulation of.🤔

If I had a house battery bank that could draw large amps (or Lithium) I would have a B2B or DC2DC. I have my direct alternator charging on an 80amp fuse. I monitor the amps into the house bank & with my typical SOC (other than a switch on spike) it will typically be around 40amps or less (65amps if more depleted & under 5amps when getting filled back up).

Per my post above I see merit in monitoring the alternator “total output current” & might look at installing a hall sensor at sometime down the road.
 

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@RV8R, I got a clamp meter to satisfy my curiosity, but it can only be used while the van is parked. A permanent monitor would provide a more complete picture. The (+) cable from the alternator runs across the front of the engine and up into the under-hood fuse box. I'd suggest mounting the hall sensor at the fusebox end to minimize heat exposure.

FWIW, I've had a cheap shunt-based multimeter from Amazon installed for several years to continuously monitor solar-controller output. It's still working and the readings are accurate enough. I wouldn't hesitate to try a similar a hall-sensor model, but it would have to handle way more than 100A. That may be harder to find (for cheap).
 
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