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Plane-Power vs B&C (2019) also: Parts info wanted

TimO

Well Known Member
I've got questions regarding alternators that I'm itching to understand.

First, if you read VAF, you'll find alternator recommendations all over the map. Some people prefer cheap, easy to replace at any auto parts store, auto alternators. Some like the simple wiring and lower cost of Plane-Power. Some like the known reliability of B&C. And, if you look, you'll find people with stories both good and bad about all 3 types. This thread is NOT AT ALL looking for a recommendation, because it'll just turn into an alternator war. It's looking to clarify some information.

Preface:
In my RV-10, I went with Plane-Powers 70A alternator, installed since day 1 with a blast tube. It's larger, heavier, and turns slower (cooler), and other than when I had the belt tension too tight and wore out a bearing, has been reliable for me. Personally, I am starting to question if the larger alternator with the bigger pulley isn't perhaps a more reliable way to go. Not lighter, not better, but perhaps more reliable.


In my RV-14, I used the 60A Plane-Power. I didn't have such good luck with that. First one died around 70-75 hours with a fried stator. Second one died at 350 TT airframe hours, due to broke brushes caused by the rear bearing to go out. This *may* have been my fault, because failure #1 was while on a trip, and I replaced it on the ramp, with no torque wrench. I would like to think I checked torque after the trip, but my memory fails me, and maybe I didn't. So it's entirely possible that I personally caused that one.

With a failed PlanePower 60A I took it to my local alternator shop, who've been exclusively doing alternators and starters for decades, looking for diagnosis, and any information on making things more reliable. Surprisingly, despite people being critical of PlanePower on VAF, they told me this: (Paraphrased) It's an ND alternator, actually not a true ND, but an aftermarket. He said ND is real good stuff and is some of the best stuff out there, and that if this was a true ND it would be bulletproof. They replaced the rear bearing, and rear case half where the bearing sits, and also replaced the brush/regulator assembly with mine that I had been carrying as spare, that is the modified by Plane-Power, crowbar module with brushes. He feels it is a good alternator and expects a good long life out of it. One thing he did mention is that they use loctite to install the bearing, to keep it from shaking in the bore, and that perhaps my bore had never been perfect which could have caused the issue of the bearing spinning. So my takeaway from this interaction is that the alternator itself probably isn't too bad, other than with it's smaller pulley and faster spin, may be more prone to fail than the 70A in my other plane. Clearly the bearings are available locally, and a local alternator shop can rebuild them, with the exception of the fact that the regulator is modified so in order to have the crowbar module you'd either need to know how to modify a stock one, or carry your own spare. I actually feel better about the 60A after having them look at it. One down side is that there is no included blast tube adapter for the 60A model. Oh, and before I forget, one of the big failure points with the PlanePower 60A seems to be it's rear connector, which is EXPENSIVE at over $100. I guess the pins loosen up.

But, still, after seeing people's reports of B&C being so reliable, I decided I would just go that route. I bought 2 B&C BC460-H alternators. I figured ultimately I should run the same alternator on both planes. Increased my ability to service with carrying spares in each plane, and makes the planes more similar. Also, I wanted to run 14.4V rather than 14.1, so figured the external regulator may indeed be nice. So I bought them. And, at OSH, I bought 2 standby alternators that I have yet to install. This should mean no trip-stopping failures in the field.

At that point though, I decided to put the BC460-H side by side with the PlanePower 60A, and that's when I became flabbergasted. Those 2 alternators look almost identical. They have the same housing, which implies the same bearing. Both are of course, small pulley light weight models. If anything, the PlanePowers aluminum pulley and bracketing on the other end actually look better than the B&C. Despite being externally regulated, the B&C has the SAME rear connector (yes, the one that's prone to fail in the Plane Power) as the PlanePower. (Although you can buy it MUCH MUCH cheaper from B&C) And, there is no blast tube mount with the B&C, and it doesn't include the bracket arm to the starter, either, whereas the PlanePowers Boss mount does. Now, if B&C is a TRUE ND, then I'd say in my mind, I'd pay price premium, knowing PlanePower is an aftermarket. But, I don't know the lineage of the B&C. I would guess they're 95% identical. There is even a regulator module in the B&C, which leads me to believe that they must open it up and either bypass or disable it, to use external control. The regulator in the PlanePower is the same module that houses the Brushes, so it is replaced all at once as a unit. You can buy the PlanePower brush/regulator model and carry it as a spare.

So this far into the post, my questions are:

** Does anyone know if B&C is a TRUE ND alternator, or is it just another knock off as well?
** Does anyone know how B&C modifies the regulator so that a person could buy a regulator and carry it as a spare? B&C by the way, does NOT sell parts, and I will not fly with it unless I can carry spare brushes and a new rear bearing, for off-field emergencies such as if I'm in Canada/Alaska/Bahamas.



Personally, my guess is, B&C built it's glowing reputation over the past many years, with many people buying the L-60 model alternator, which is no longer current. This BC460-H is a "new" model, and my guess is that the physical, non-regulator type failures will become very similar to the PlanePower 60A over the course of the next few years. A smaller, faster spinning alternator likely will last a shorter lifetime than a larger slower spinning alternator. It's just a guess, but it will be interesting to see the statistics from present day going forward.

With a standby alternator, I'm not going to be nearly as worried, but both planes will now be heavier, as well, with one more maintenance item to fail, so it won't be cheaper.
The regulators used for both B&C alternators have the benefit of being able to live on the cold side of the firewall, which is great. But, they also are considerably large and not completely insignificant for weight. If weight and space are your biggest concern, the PP60A is going to be more attractive. I'm guessing that reliability wise, you probably couldn't beat a full size 70A alternator that's the physical size of the PP70A, but externally regulated with a B&C regulator. But that's just a guess.

If it were easy to get a boss mount for an auto alternator, I may have been interested in going that route, but, I wanted to stick with an alternator that came with the bracketing to mount to a lycoming, so that's why I don't consider other options. I do though, want to find out everything I need to know, to be able to carry a spare set of brushes for my BC460-H, and if that means taking a brand new alternator to an alternator shop and having them pull it apart, so be it. I just figured that maybe someone on here would already have a source for the BC460-H brush/regulator assembly, and know how to bypass/disable the regulator so it can be externally regulated.

I guess in the end, a person could, in an emergency, just put in an internally regulated module in the B&C and bypass their B&C regulator if you needed to get home. Knowing of course that you then lose the crowbar OV module. Or perhaps you could still run your B&C regulator, trying to regulate the internally regulated alternator to 14.4V, but the alternator would then regulate that back down to 14.1, sensing that it was running high on the field terminal. Not sure.

I do think it'll be interesting though, to see if the new B&C keeps their reputation glowing, or not. I suppose it all depends on if the similarities between them and the PP60A are more than skin deep.
 
I don't know the answer to your questions but I have had a great luck with B&C alternators, first a 40A in my RV7A and currently at around 1000 hours and second a 60A in my 14A but only 90+ hours. For me the real trouble with alternator failure is not the cost but the hassle, especially if you are not at your home airport and on a trip. So far, I have not had a smallest hiccup with either and that is worth a lot of $$$$ for me.
My RV7A had a starter failure at the first 100 hours away from the home airport. They replaced it for free and under warranty but the cost of back and forth to that airport was more than two starters worth of $$$
 
Tim,
I cannot speak to your RV 10, however I completed my RV14-A last year and have 183 hours logged. Recently my new gear driven (secondary) Plane-Power model FS1-14B failed. While inspecting the alternator it was very apparent that the case mount was internally separating.

I called Tim Gauntt at Hartzell and learned they have corrected manufacturing problems from the past with the belt driven units starting sometime in 2017. They are finalizing issues with the gear driven alternators now. Tim can give you the details. B&C will also answer your questions.

You have a lot of good questions that would best be answered by Hartzell and B&C. In my conversation with them, it sounded like Hartzell is committed to making their acquisition of Plane-Power a more reliable product. They are replacing my alternator in the next few weeks. With many all electric glass airplanes, we need bulletproof alternators more than ever.

I would like to see your questions answered by the respective companies. Past performance is important but we need to also understand future reliability when ownership and products change.
 
You hit my points exactly. Both of you. For me, #1 is reliability because I don't need the inconvenience of having an issue on a trip. From a safety standpoint I think I'm fine getting it on the ground without the alternator.

But, I would believe that both companies would be trying to ensure they have good reliability, and it's great to hear Hartzell has made changes to the 60A that may improve things there. My intention wasn't to slam either company at all, but basically question what the real differences are, going forward, since I now know the PP isn't a true Denso, and I am curious if the B&C actually is or not. If not, I personally think that other than things they can tweak internally for better reliability, they will probably have similar failure rates going forward. I'm betting that the L-60 was a whole different animal. It had the .250" spade connections (better reliability I would think), and it was 1.6 (or so, from what I hear) pounds heavier, which indicates it may be larger. So I figured maybe that's why B&C got the good reputation. It was superior hardware in that case.

But, once someone has info on the guts of the BC460-H, it may indeed have something internal that's different that would make it "better". Otherwise, it's just another alternator and shouldn't really be "better" by design. Only time will tell I suppose.

I do, however, want to ensure I can carry spare brushes and bearings, so one way or another I'm going to have to either tear one open or hear from someone who has.
 
Hey Tim,

Maybe you could post some pictures of each unit to aid in identifying their respective origins?

FWIW, I have heard that the Plane Power OEM is Unipoint. However, I haven't been able to prove or disprove that.
 
One other factor that I forgot to mentioned, though I don't have the data available to collaborate my opinion, but it seems to me that a good portion of alternator failures are as a result of failure of their [internal] regulator and with B&C regulator mounted on the cold side of the engine, this reliability has been far higher.
 
Tim: was your first PP made before, and second PP made after, the change in ownership of PP? Think that caused any changes, pro or con?
 
The B&C main alternator on my RV-10 has been going now for 10 years and 1700 hours. :)

I've replaced many other brands of alternators on customer's airplanes over those same years, with 1/3 or less time on them than this one.

Just my experience. :)

Vic
 
Ok, here's some pics and info.

First, comments:

Vic, I hear ya. The thing is, your data point probably isn't worth anything in the discussion. (ABSOLUTELY no insult intended) The reason? Well, your B&C being 10 years old isn't the same model as what they sell today. That's exactly my point and concern. The highly positive reviews may be based on more reliable hardware than what we have for choices in 2019. If they still sold that one, I would have gone that route, for sure, because you're right...your generation of alternator had good reliability. Don't feel bad though, that's the same reason my 70A PP isn't worth talking about much. It's been more reliable too, and isn't the same animal.

Regarding Bob's question, I think both of mine were made after the change in ownership, although I can't say I know when that was. The one that failed with a bad stator short was installed in 2015 before I flew. The one that failed now was one that I got from another builder in 2016, who was building his plane. I stole it when I was AOG and sent him a brand new in box one. So I guess to be honest, I don't know the exact age as it's not printed on the alternator, to my knowledge. Hearing they made recent improvements, I would feel better about new ones than old ones I guess.

Regarding Mehrdad's comments, that's not what I found when searching threads. I didn't hear much of anything about failed regulators in the PP's, but heard tons of connector pin failures, and many stator coil failures. The connectors being the same as the NEW B&C, make me wonder if we won't start hearing of failures in those now too, simply because it's a different connector than those like Vic would have on his plane.

Anyway, here are some pics of them side by side. The PP has a larger bump on it's back shroud, but otherwise dimensionally they are the same. That's cosmetic because there's nothing under the bump. Also, the cases themselves are nearly identical, but, the mounting area is beefed up on the PP with some machined pieces. Makes it LOOK heavier duty, but in practice I doubt it does much. The other difference is just the pulley. Otherwise, you'll find them almost clones of eachother.

PP_and_BC_01.jpg


PP_and_BC_02.jpg


PP_and_BC_03.jpg


PP_and_BC_04.jpg


PlanePower Regulator:
PP_Reg_01.jpg


PP_Reg_02.jpg


PP_Reg_03.jpg
 
I remember years ago when I talked to them to learn more, they pointed out the "three attachment points" that they had learned as a factor for longevity/reliability.
I would be very interested if the newer alternator which I also have in my 14A will have the same reliability as the last one.
 
B&C still carries the "original" L-40 which is what I continue to run, until the newer units prove their reliability I'll stick with the good old 40 amp unit plus you save a little weight as well.
 
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I have 2 B&Cs on my RV7A, an L40 up front and a 20amp unit on the accessory case. Both units 460 hours without any problem at all. And I have dual busses with my 20 amp unit running during normal operations.
I remember when I spoke to Bill Bainbridge at Oshkosh in 2006 he said B&C dynamically balances every alternator before it goes out the door. Bill struck me as very knowledgeable and a person of good integrity so I bought his products. So far so good.
 
Ok, here's some pics and info.

First, comments:

Vic, I hear ya. The thing is, your data point probably isn't worth anything in the discussion. (ABSOLUTELY no insult intended) The reason? Well, your B&C being 10 years old isn't the same model as what they sell today.

None taken; however I wouldn't be so quick to dismiss a company that has had great products for a very long time in a a specific area that we seem to have some concerns for reliability. I've been installing the new ones for a few years now on customers' airplanes with no problems. I even have one of the newer backup alternators on mine.

Still seeing the same great reliability. :)

Vic
 
Tim Did you get my email?

BTW - look at the clocking of the adjustment arm lug vs the attachment lug for the B&C. That clocking is the same as the units rocket bob promotes. 180 deg.

Now, note the PP. The adjustment arm is rotated maybe 15 deg to allow a straight adjustment arm. Not necessarily better, but it shows the front housing difference. The PP housing has the same clocking as the '95 tercel, but the bearings, in particular, are not at all the same.

I have found that even if they look the same on the exterior the bearings can be much different. The Tercel bearings are much larger than the PP. The rotor, died bridge, and stator are the same though. I have a new set of Tercel bearings if someone needs them.

The SRE housings seem to be the same for the B&C and PP.

The stator retention bolts - both alternators have two (2). That bolt has a nut holding the cases together.
 
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A few answers and another alternative

Tim,
The old Nippon Denso alternators with the round 3 terminal connector in the rear were used up to the 1992 model year. The oval 3 pin connector with the reduced width pins, started in the 1993 model year. I believe on most cars that connector style lasted for less than 10 years. There's no hard-and-fast year cutoff as different manufacturers used that connector for different lengths of time. So while that connector is newer than the old round style, it is nowhere near the newest style Nippondenso automotive alternator. In the automotive world to save money & to save weight, they've been making fuses and electrical connectors smaller and smaller over the years. This reduction in connector size has not been without pitfalls. The rate of problems with poor connections on the smaller connectors has gone up over the years.
There is another option however. You actually can have your cake and eat it too, sort of. It has nothing to do with B&C or PlanePower. During the 1990s Nippondenso actually did have one automotive customer who wanted a high output, quality Nippondenso alternator that would use an external voltage regulator. That customer was Chrysler Corporation. So if you want to have a Nippondenso alternator that's externally regulated but you don't have to do surgery on, go to your local favorite auto parts store and order an alternator for a 1995 Dodge half ton van. These trucks came with a V6 and V8 engine option. Engine doesn't matter. Both the V6 and V8 were available with a 90 AMP or 120 amp alternator. You want the 90 AMP unit as the 120 amp unit is considerably more expensive. These alternators are physically and externally similar to the 70 amp alternator that you used to have on your RV 10. The one difference is there's no internal voltage regulator. Where other Nippondenso alternators have a voltage regulator, these Chrysler units have a terminal block with two studs for wires to go to your external voltage regulator. On the original trucks the external voltage regulator was actually built into the PCM aka engine computer. Chrysler installed a temperature sensor under the battery so that the computer could monitor battery temperature and modify the field voltage to compensate for a battery that was getting too warm.
Now you have an alternator that you can purchase with a lifetime warranty and not have to void the warranty to obtain external voltage regulation. One modification will need to be done however. This won't void the warranty as its external and you can ask the guys at the parts store to do it for you. You need to swap the serpentine belt pulley that comes on these alternators for the V belt pulley that you need. The guys behind the counter at the Big Chain stores are usually more than happy to do this for you. Save the original pulley, so that if you have to make a warranty claim, you can swap the original pulley back on. You'll need your V belt pulley to install on its new replacement anyway.
I can tell you that B&C completely strips thier alternators down. That's because that golden color indicates that they Alodine the alternator cases while it's apart. That's a nice touch to help prevent corrosion without holding in heat or adding weight. The PlanePower alternator in your photos has been painted silver, as are most Automotive remans.

Charlie
 
Some more good replies, thanks all. I don't have any issue with B&C or Plane-Power alternators, as far as companies go, so it's not that I'm actually uncomfortable with either. Personally, I think any of these options are OK. I'm just questioning if they're ideal. Charlie's post kind of illustrates that with his discussion of the connector type being used. I'm sure that either company can have good reliability, and it depends on many factors, some require the builder to use their skills properly too.

I do like Charlie's info about the Chrysler alternator. It's too bad someone doesn't make a boss mount kit for those, so that you could just buy the boss mount kit, and buy the alternator and pair that with a B&C regulator. That actually sounds like a great way to go.

But, right now, I own 4 plane power alternators, and 4 B&C alternators, and I'm going to be installing the B&C, whether it leads to better reliability or not. I always laugh when someone says they've had good luck with XYZ's component, and it's been going strong now for over 380 hours. To me, if you don't have 1000 hours on the product without failure, you can't really speak to reliability. Certainly not less than 500. People like Vic, who have tons of time on components, are the ones who have the reports I trust the most. I've got that many hours on my PlanePower 70A, but no other product, which is why I've got the questions I do, not answers.

Actually, I would like to modify my statement just slightly on my views on the vendors. Like I said, I really don't have any issue with Plane-Power or B&C. B&C has a great reputation and they deserve it. But, if there's one thing that does turn me off a little, it's the fact that I can't even buy a brush set for their alternator. You can buy one for the Plane-Power from Aircraft Spruce. I wish they'd consider selling those parts. I'm not traveling without spares, so that forces me to open one up, find out what part I need, and order it elsewhere, which is not something that makes me happy. Other than that, I think the company does a great job, and I trust their product. I think I will also carry a spare connector plug, so my carry along spares would be a bearing, a brush kit, and a connector. If I'm out of the 48 states, I don't want to be stuck for a few days with no way to get home.

The point from Walt is also good on the L-40. I myself would rather stick with 60A even though I don't need more than 40, but, I don't know that it's going to be a good option for some builders. Here's a twist that I've seen lately:

A couple of friends who've went with EarthX batteries have 60A PP alternators. When they first start up, those alternators are being pushed to their limits because the Lithium batteries are soaking up all the current they can. I see a couple of issues with this. 1) I don't think alternators really should be run to 100% capacity for very long. I'm sure it affects reliability and maybe longevity. One of my friends has had diodes go bad for sure. 2) I don't know that it's even good for the battery to be allowed to soak up that much current that quickly. People love quick charging, but even with your cell phone or your car, manufacturers now are understanding that if you want longevity out of your batteries, keep them between 20-80% capacity and avoid quick charging especially if they get hot.
Given that we're just starting to see the new batteries be used in aviation, we may start to see new trends in failures if we use smaller alternators. Time will tell I guess.

Hopefully over the next couple weeks I'll have at least one plane's alternator swapped out, and the backup alternator installed, and I will have one less concern when traveling. The backup is probably the key to reliable dispatch.
 
While Denso clones may look alike externally and even internally, they are not in fact Denso as has been pointed out in these discussions before.

Ever wonder why brands like Toyota generally use Denso and not something less expensive?

My suggestion to PP to restore past performance to present offerings, is to use genuine Denso components. The components they have been using lately were not up to snuff given the failure rates reported on VAF.

When you outsource, you best have a complete engineering review of the components, process control, QC and independent validation and testing to be sure the product meets original durability and performance or it may come back to bite you.
 
Another data point:

My PP 60 amp internally regulated alternator failed after 340 hrs (purchased in 2016). They replaced it under warranty and it would have been very easy to put the new one on my plane but it now has the B&C L40 with external regulator in the cabin.

On another note: Anyone interested in purchasing my new PP alternator?
 
A picture is worth a thousand words

Charlie,
Will the Chrysler alternator fit into the B&C boss mount?

Follow the link below. Look for the small photo of the alternator and tap on it to get multiple views of the alternator. You will see how the mounting system is set up. It has a bracket coming off both the front and the rear half of the casing. The rear leg of the mount also has a sliding bushing which allows it to adapt to mounts of varying lengths. Pay attention to the rearview and you'll see up near the top where the two terminals studs for the external voltage regulator are.

https://shop.advanceautoparts.com/p...6-P?navigationPath=L1*14920|L2*14999|L3*15587

Charlie
 
More info to muddy the waters even further

I just stumbled across this article. For those with standard flooded acid batteries don't bother reading it it doesn't really pertain to you. However if you have an AGM battery or a lithium battery you might want to read the section titled internal Regulators versus external regulators.

https://www.westmarine.com/WestAdvisor/Selecting-an-Alternator

Those of you with more cutting-edge technology batteries might want to consider using a voltage regulator that can measure the temperature of a remotely mounted (rear) battery. I haven't done much research on this. However I've stumbled across one or two marine and Automotive voltage Regulators that have this capability.

Just food for thought and worth exactly what you paid for it.

Charlie
 
Chrysler alternator

I have been looking at the Chrysler alternator, online, for some time. Specifications list the weight at 12 pounds? Does the PlanePower pulley fit the shaft diameter? Is the housing small enough to fit in the space?
 
Another data point:

My PP 60 amp internally regulated alternator failed after 340 hrs (purchased in 2016). They replaced it under warranty and it would have been very easy to put the new one on my plane but it now has the B&C L40 with external regulator in the cabin.

Smart move, You won't regret it.
 
I have been looking at the Chrysler alternator, online, for some time. Specifications list the weight at 12 pounds? Does the PlanePower pulley fit the shaft diameter? Is the housing small enough to fit in the space?

Yes the PlanePower pulley will fit the shaft on the Chrysler alternator. The Chrysler alternator is the same physical size as the 70 amp Nippondenso that the original poster reported having installed on his aircraft. That said, I have no idea if you could get it to fit on an RV 3 or an RV 4 due to their extremely tight cowls. ( most likely not)

Still another option would be, purchase a 70 amp Nippondenso alternator for a 1992 Toyota Camry. That was the last year that had the round style electrical connector on the back. For about $15 you can purchase the brushes, brush holder and terminal block for the Chrysler alternator and retrofit them into that Camry alternator. The terminal block replaces the internal voltage regulator. That is a totally bolt-on modification other than the slight modification you'll have to do to the sheet steel back cover on the Camry alternator. You have to cut open a rectangular hole in that cover for the two electrical terminals on the terminal block. Contact me via private message, with your email address. I can email you photographs of that mod.

Charlie
 
I have been looking at the Chrysler alternator, online, for some time. Specifications list the weight at 12 pounds? Does the PlanePower pulley fit the shaft diameter? Is the housing small enough to fit in the space?

Do you know if that 12 pound weight that you quoted is the actual weight of the alternator or shipping weight ? I would suggest you also check the weight of that 1992 Camry alternator. There might be a weight advantage in simply converting that one. As a general rule, the weight of an alternator will go up when they increase its power output. That is due to the fact that they have to increase the number of windings in both the rotor and the stator. Those extra windings add weight.

Charlie
 
Regulator Source

<snip> They replaced the rear bearing, and rear case half where the bearing sits, and also replaced the brush/regulator assembly with mine that I had been carrying as spare, that is the modified by Plane-Power, crowbar module with brushes. </snip>

Curious where you sourced your spare Plane Power modified regulator?
 
Substantial alternator choice

Do you know if that 12 pound weight that you quoted is the actual weight of the alternator or shipping weight ? Charlie

The shipping weight listed is 14 pounds. I figured that more copper and a large housing equals more weight. Swapping parts sounds like an attractive choice.
 
Dan, the spare regulator I got from Aircraft Spruce, for my Plane-Power. You may want to verify that this one is for the 60A experimental alternator, but I think it is, based on the timeframe that I ordered it. I bought one for my 70A long ago. I purchased one of these on 8/24/16:

11-1043 HARTZELL PLANE-POWER REGULATOR BRUSH ASSY 07-17968
$79.85

It comes complete with a new regulator, brushes, and the pin side of the connector. (Not the plug side of the connector that the wire harness is attached to.)

I carried it with me and when I had my 60A rebuilt recently, they replaced it with my spare.
 
Charlie, thanks a ton for sharing the link to that West Marine article. This is EXACTLY what I was guessing when I said I think we'll see some differences going forward, as people put in Lithium type batteries. They may not realize that their alternator choices may need to be changed. That article explains things very well.

This part specifically has some information that applies to us as well, with our alternators being close to exhaust:

Temperature ratings are often determined using a military standard of 122?F, measuring the ambient air temperature in the vicinity of the alternator. Sustained operation in hot engine room conditions will reduce alternator output. A hot alternator, operating at approximately 180?F?200?F will only supply about 80 percent of its rated capacity. Large-frame models generally run cooler than their smaller siblings because of their ability to dissipate heat. Small case alternators are not designed for continuous high-output operation.​

I just checked out the earthx pae and see that their ETX680 says 60A alternator or less, whereas their EXT900 says 80A alternator or less. The "or less" part is a little confusing or maybe misleading. You would think they should phrase it differently, like maybe one would need a 50A alternator "or more". A couple of my lithium equipped buddies are able to fully max out their 60A alternators with their batteries. I'm not sure if they are the 680 or 900. But, for the first part of the flight, they're pulling full capacity. Now, if you are looking at a hot day, or hot start, and start taking into account hte temperature ratings, you could really be over-taxing an alternator. I'm sure since it's not a long-term load it will work out for many people, for quite a while. I just think that long-term, it may start to change some of the trends we see in alternator longevity.

Sorry, that got off on a whole tangent that I didn't really intend. But, it just shows how important it is to look at the complete big picture when you choose components for your plane. Personally, I would think it smart to go with a bigger alternator in the case of lithium batteries. What would be nice is if there was a way to have a more controlled charge, but a full-power discharge capability for them for starting. After all, it's less desirable to charge any battery at super high charge rates, if you can avoid it. My normal running load on my planes is about 22A. A 60A alternator works great for that. I personally would love to keep my alternator load below 80%, or 48A, if possible, at all times.
 
You have really summed the issues up

Tim,
Your "rant" as you call it, really contains a lot of excellent information. People who aren't knowledgeable about electrical or electronic matters generally think that a 60 amp alternator is a 60 amp alternator. Not true! Those nice small lightweight alternators that generate the same amperage??? Do you really think that you're getting something for nothing? ( the same power for less weight). There's always a trade-off. In the case of lightweight alternators, some of the components have to be made smaller. Specifically the brushes and the diodes in the rectifier Bridge. There are always exceptions but as a general rule when you make a diode smaller, it can't handle as much power OR it's fragile under high power loading. And the smaller ones that can are $$$! You're very wise to say you want to keep your alternator output below 80%. That will go a long way towards improving the longevity of your alternator.
I stumbled across that article while doing a search to see if I could find an automotive or Marine external voltage regulator that offered both alternator and battery temperature sensing. Those Builders using lithium technology batteries should strongly consider installing a voltage regulator that can monitor both the alternator and the batteries temperature. Modern internally regulated alternator have the capability to monitor the temperature of the alternator itself. Many of the automotive manufacturers simply figure that since the alternator and the battery ( assuming the battery is under the hood) will be operating at similar temperatures. I strongly suspect that the folks on this list who are reporting short alternator lives probably do not have adequate heat shielding to protect the alternator from their exhaust system.

Charlie
 
The ultimate external voltage regulator???

Tim,
West Marine touts Balmar brand alternators and voltage regulators. The Balmar model MC-614 multi-stage voltage regulator has an amazing list of capabilities. I suggest you download the installation and operation manual for it and read up on it. It can monitor alternator temperature, it can monitor dual battery temperatures. It has multiple programmable charging strategies for all the different battery technologies that are available today. Really quite amazing piece of equipment. However I was doing this research at 3 AM. I seem to also remember in another Ballmer document saying there was a Prohibition against using this voltage regulator with crowbar over-voltage protection. That's why I hadn't mentioned it earlier. If you have the time, look for a document produced by Balmars tech support. I think that's where I read about the prohibition against crowbar over-voltage protection. That said, this unit can't be the only product of its kind of available on the market. I'm sure with some research we can find others.
I almost forgot, in my research I found Balmar gives a good rule of thumb regarding sizing alternators to batteries. The rule of thumb is this. For standard flooded acid batteries the alternator should be sized so that its output is 25% of the batteries capacity. For gel cell and AGM batteries I believe it's 45%. For lithium batteries it's 50 to 60%.
Charlie
 
I just checked out the earthx pae and see that their ETX680 says 60A alternator or less, whereas their EXT900 says 80A alternator or less. The "or less" part is a little confusing or maybe misleading. You would think they should phrase it differently, like maybe one would need a 50A alternator "or more".

The reason they limit the alternator output is because their battery management system doesn?t limit charge current. Lion batteries have a very low internal resistance and will take very high charge currents. So, if for example, you have a 100 amp alternator, and you had a partially discharged battery from starting, the battery will accept all 100 amps. Sounds great, but this heats up the cells and can cause battery failure. Therefore they limit alternator output to a value that they know won?t toast the battery.
 
That makes sense, thanks Dan. So basically it's got a narrow operating envelope if you look at it that way. On one hand, you don't want too large an alternator, or you can destroy the battery with too much charge current. On the other hand, if you get too small an alternator, you may cause early death of your alternator due to the alternator running hot or working too hard. So given that, the 40A model is probably not good for a Lithium install, and you would want to pick the best battery size for your 60A or 70A alternator. It's too bad they don't have a current limiter on the input. It would make the alternator choice a little easier.
 
Lester numbers

Tim,
snipped. During the 1990s Nippondenso actually did have one automotive customer who wanted a high output, quality Nippondenso alternator that would use an external voltage regulator. That customer was Chrysler Corporation. So if you want to have a Nippondenso alternator that's externally regulated but you don't have to do surgery on, go to your local favorite auto parts store and order an alternator for a 1995 Dodge half ton van. These trucks came with a V6 and V8 engine option. Engine doesn't matter. Both the V6 and V8 were available with a 90 AMP or 120 amp alternator. You want the 90 AMP unit as the 120 amp unit is considerably more expensive. These alternators are physically and externally similar to the 70 amp alternator that you used to have on your RV 10. The one difference is there's no internal voltage regulator. Where other Nippondenso alternators have a voltage regulator, these Chrysler units have a terminal block with two studs for wires to go to your external voltage regulator. On the original trucks the external voltage regulator was actually built into the PCM aka engine computer. Chrysler installed a temperature sensor under the battery so that the computer could monitor battery temperature and modify the field voltage to compensate for a battery that was getting too warm.
snipped
Charlie

The Lester number for this alternator is 13354.

The Lester number for the 1992 Camry 70 amp alternator that I also mentioned earlier is 14849. This is an internally regulated alternator that can be converted to external regulation without any major surgery. It's a simple matter of removing the internal voltage regulator and the brush pack and replacing them with the terminal block and brush pack for the Dodge van alternator. Cost for the conversion Parts is about $15.

Charlie
 
It doesn't weigh 12 lb according to Advance Auto Parts

I have been looking at the Chrysler alternator, online, for some time. Specifications list the weight at 12 pounds? Does the PlanePower pulley fit the shaft diameter? Is the housing small enough to fit in the space?

Jim, I sent a question to Advance Auto Parts asking them the weight on both the 90 amp alternator designed for external regulation for the 1995 Dodge van and also for the 70 amp alternator for the 1992 Toyota Camry. Surprisingly the 90 AMP Dodge van alternator is lighter. According to Advanced, it weighs 10 lb. The 1992 70 amp Toyota Camry alternator weighs 12.6 lb. I guess that's not surprising when you look how massive the mounting points are on it.

Charlie
 
A few points. If your engine is in proper tune, you shouldn't have to turn it over for more than 5 seconds. This takes very little out of the battery and therefore won't result in very high charge current from the alternator to replenish it in the first minutes.

If you're concerned with too much charge current, keep the engine at idle for a minute or so. A 60 amp alternator will be lucky to produce 30-35 amps at slow idle.

If you run a lithium battery and it's really discharged for some reason, think about delaying your flight and getting a low rate charge on it for a while and be sure you know WHY it was so discharged to begin with. If you're electrically dependent, treat that battery with respect and care. Your life may depend on it.

If you firewall mount your battery, be aware that it will almost certainly see temps over what the manufacturer recommends without some air blast cooling. High temps reduce life and may have more serious consequences in some cases with certain battery chemistries.
 
An interesting data point on alternator reliability, from the automotive world.

My 2000 Chevy Astro Van went 180,000 miles on its first alternator. It failed last month. Not feeling like working on the van (poor access to most everything on the front of the engine) I paid a shop to replace the alternator. At the time, I walked out of the shop thinking that was the most expensive alternator I ever bought (because of the installation labor charge).

Today, that new alternator failed, after just a couple of hours of run time. Infant mortality I guess. The shop said it was "highly unusual". He wasn't sure if it was an ND or a Bosch (he wasn't the tech that did the replacement). This time I walked out thinking it was the best deal I ever got on an alternator, because I didn't have to go through the chore of replacing it twice!

I don't know the exact failure process, but I can tell you that it made a distinct whine/whirring noise, and then started to smell strongly. Then I noticed it wasn't charging.

I don't know if this experience is relevant to any of our alternators or not.
 
Likely the brushes finally wore down to a nub, tilted in the holder and you heard the "ping" as the wires snapped off them as the parts got carried through the spinning rotor.

This is the most common failure on high mileage Hitachi and Denso alternators at least that I've worked on for several decades. In fact, about the only type of failure I've ever seen on them and I used to run an auto repair shop for mainly Japanese brands eons ago.

The Hitachi in our shop car had 360,000 km on it when the same thing happened to it. Let's call that around 6000 hours.
 
A Data Point

A few points. If your engine is in proper tune, you shouldn't have to turn it over for more than 5 seconds. This takes very little out of the battery and therefore won't result in very high charge current from the alternator to replenish it in the first minutes.

If you're concerned with too much charge current, keep the engine at idle for a minute or so. A 60 amp alternator will be lucky to produce 30-35 amps at slow idle.

If you run a lithium battery and it's really discharged for some reason, think about delaying your flight and getting a low rate charge on it for a while and be sure you know WHY it was so discharged to begin with. If you're electrically dependent, treat that battery with respect and care. Your life may depend on it.

If you firewall mount your battery, be aware that it will almost certainly see temps over what the manufacturer recommends without some air blast cooling. High temps reduce life and may have more serious consequences in some cases with certain battery chemistries.

I did some ground testing with my Plane Power 60 AMP alternator, and it will produce nearly a full 60 Amps at 1000 Engine RPM!

Skylor
 
Apples to oranges comparison

An interesting data point on alternator reliability, from the automotive world.

My 2000 Chevy Astro Van went 180,000 miles on its first alternator. It failed last month. Not feeling like working on the van (poor access to most everything on the front of the engine) I paid a shop to replace the alternator. At the time, I walked out of the shop thinking that was the most expensive alternator I ever bought (because of the installation labor charge).

Today, that new alternator failed, after just a couple of hours of run time. Infant mortality I guess. The shop said it was "highly unusual". He wasn't sure if it was an ND or a Bosch (he wasn't the tech that did the replacement). This time I walked out thinking it was the best deal I ever got on an alternator, because I didn't have to go through the chore of replacing it twice!

I don't know the exact failure process, but I can tell you that it made a distinct whine/whirring noise, and then started to smell strongly. Then I noticed it wasn't charging.

I don't know if this experience is relevant to any of our alternators or not.

Steve, your experience shows that Nippon Denso alternators aren't the only ones that can provide excellent service. Your Chevy came with an alternator that was manufactured by what used to be the Delphi division of General Motors. In 2009 General Motors spun off the Delphi Division and they now an independent Corporation. The fact that the reman alternator came in a box that said Nippon Denso or Bosch doesn't mean that that is the corporation that actually originally manufactured the alternator. That just means that the alternator was remanufactured by a Rebuilder who is approved by Nippon Denso and or Bosch.
The description of your replacement alternators failure sounds very much like a shorted stator. Most electronic devices that have a manufacturing defect will fail within the first 6 weeks of service. Most retail Electronics have a failure rate of about 6% during that first 6 weeks.

Charlie
 
A few points. If your engine is in proper tune, you shouldn't have to turn it over for more than 5 seconds. This takes very little out of the battery and therefore won't result in very high charge current from the alternator to replenish it in the first minutes.

If you're concerned with too much charge current, keep the engine at idle for a minute or so. A 60 amp alternator will be lucky to produce 30-35 amps at slow idle.


My experience differs quite a bit from this. The current generation of alternators (PP and B&C) that I have tested will put out full rated amps at low idle on our airplanes, except the stnadby alternators on the vacuum pad. Even with a very quick start the lithium battery will take a full load for a few seconds, so it is not uncommon to see 60 amps for 10-30 seconds after a startup. I tell new owners of lithium batteries to not be concerned, as it is normal operation.

If you've sat there for a while with the power on prior to engine start while you o perform a checklist or receive a clearance, the high amp load will last much longer, perhaps a minute or 2. Usually by the time the runup is completed, the charging output is back to normal, around 20 amps or whatever your wsteady state load happens to be.



Vic
 
A few points. If your engine is in proper tune, you shouldn't have to turn it over for more than 5 seconds. This takes very little out of the battery and therefore won't result in very high charge current from the alternator to replenish it in the first minutes.

If you're concerned with too much charge current, keep the engine at idle for a minute or so. A 60 amp alternator will be lucky to produce 30-35 amps at slow idle.


My experience differs quite a bit from this. The current generation of alternators (PP and B&C) that I have tested will put out full rated amps at low idle on our airplanes, except the stnadby alternators on the vacuum pad. Even with a very quick start the lithium battery will take a full load for a few seconds, so it is not uncommon to see 60 amps for 10-30 seconds after a startup. I tell new owners of lithium batteries to not be concerned, as it is normal operation.

If you've sat there for a while with the power on prior to engine start while you o perform a checklist or receive a clearance, the high amp load will last much longer, perhaps a minute or 2. Usually by the time the runup is completed, the charging output is back to normal, around 20 amps or whatever your wsteady state load happens to be.

Vic

I ran some actual numbers here.

Average drive ratio is about 3.9 to 1. Using an alternator test graph I have on my 70 amp ND alternator, it generates 51 amps at 2500 rotor rpm (641 engine rpm). Starter draws around 150 amps for 5 seconds which is 12.5 amp/ minutes. That would mean the alternator would top up the battery in about 15 seconds with no other load on. Nothing is going to get very hot in 15 seconds.

You could slow this rate down by throwing on extra load before turning the alternator on.

My estimate of of 30-35 amps was based on my installation which has a much smaller pulley ratio than the average Lycoming installation. My bad there.

This again speaks to the advantage of larger alternator pulleys, both to reduce bearing and brush wear, and charging rates at idle for more sensitive Lithium batteries. Dropping the rotor speed to 1500 rpm at idle would drop my alternator output to around 23 amps.
 
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Good information above on alternators and Earth-X batteries. Every airplane has unique electrical systems. I decided to test and log my amp draw at the time of engine start-up. The following is my Hartzell (PP) Alternator, Earth-X battery and Garmin G3X system results:

Airplane RV14-A- ALT Test:
Actual AMP Draw for Hartzell/PP (AL12-C60) Alternator - Serial # date code ?S?= 2018
Hartzell date code ?R?= 2017 and later are improved manufacturing process. (According to Hartzell)
Battery: Earth-X; ETX-900 (15.6 ah) 13.2 volts; CCA AMPs 400 (4.9 Lbs)
Test Date: Nov 4 2019
Airplane Status: hangered for 48 hours (cold)
Ambient air temp when started: 70 F
Engine Start Procedures Used:
ON: TCW ? IBBS-12v-6ah Backup Battery ?(G3X Checklist reviewed, ATIS)
ON: G3X Touch GDU 460 screens and GEA 24, GSU 25 ? (120 seconds IBBS)
Master- ON for 30 seconds, Strobes- ON; Fuel pump- ON
Started Lycoming IO-390 ?
Hartzell (PlanePower) 60 amp Alternator amp draw results displayed on G3X:
48 amps ? first 7 seconds, then Alt draw drops to 23 amps for 10 seconds, then 13 amps for 15 seconds.
Avionics and AP Masters ? ON ? (Garmin IFR GTN 625, Dual VHF?s, GTX 45R, GMA 245, others).
Engine RPMs =1000 - Hartzell/PP (AL12-C60) Alternator Amp Draw - 9 amp load after 2 min.
9 amp load includes recharging: TCW ? IBBS-12v-6ah Backup Battery
Add: 5 amps for the Garmin Pitot heat if needed; 3 amps for the Fuel Pump and 2 amps for the LED Land lights.
Normal in-flight alternator amp draw is 9-10 amps. (No fuel pump, pitot, defroster or landing lights)
Full Amp draw with every switch in the airplane- ON = 22 Amps in-flight at 2300 RPMs.

My alternator and Earth-X 900 seem to be a good match for the Garmin G3x IFR panel given the 10-20 amp normal draw. Every airplane is different, I would be interested to see results of other similar electrical systems.
 
low voltage regulator to lower charging amps

Is there a simple/cheap external regulator that's 2-stage?

Initially have a lower voltage so that the charging amps (and alternator output) is lower.


I suppose you could have 2 (switchable) external regulators. lower voltage could then be a hot spare.
 
Tim,
So if you want to have a Nippondenso alternator that's externally regulated but you don't have to do surgery on, go to your local favorite auto parts store and order an alternator for a 1995 Dodge half ton van. These trucks came with a V6 and V8 engine option. Engine doesn't matter. Both the V6 and V8 were available with a 90 AMP or 120 amp alternator. You want the 90 AMP unit as the 120 amp unit is considerably more expensive.

Not trying to thread drift, but adding this bit of info - that 90 amp alternator Denso p/n is 210-0143. Turns out it is the optional high output alternator for the '95 Dodge line; the standard Denso alternator 210-0682 is a 75 amp unit, which matches nicely with EarthX's recommendations to limit to 80 amp alternators for the ETX900 battery. My intention is to pair with the B&C LR3C-14 regulator as I have one in my other aircraft, and to have an easy swap option if necessary.
 
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