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question about electrical

That's a Great price Don. I would expect to pay something in the $120 range (msrp) for a Genuine HD battery.

Don, Be sure to send those people a Christmas Card!:)
 
That's a Great price Don. I would expect to pay something in the $120 range (msrp) for a Genuine HD battery.

Don, Be sure to send those people a Christmas Card!:)

Hoople I buy that whole dealership pizza from time to time. They send me Christmas and B'day cards.
 
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I often wonder why so many people find it to be a contest to see just how many years they can "wrench" out of a battery. That's a sure way to deep six your regulator & stator.
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Hoople is it the increased heat that comes from the higher amp output of the stator that causes it to deteriorate (or melt) ?

Is it kinda the reverse induction scenario of electric motors overheating from slowed (or locked ) rotation of the armature from too high a load, causing amperage and heat to rise.

Hoople I buy that whole dealership pizza from time to time. They send me Christmas and B'day cards.

Maybe I should try that, ... ... nah just buying the Tshirt would be cheaper. But seriously that's a very generous and nice thing to do. I've never really viewed them as anything other than a business. You obviously have a great relationship with them.

I do give to the Salvation Army though.
 
is it the increased heat that comes from the higher amp output of the stator that causes it to deteriorate (or melt) ?

That's an involved question with lots of pieces to the answer. Here are some facts and some theory behind the answer.

Everything I have seen indicates the late model 3 phase charging systems are series regulators and not shunt regulators as the early single phase may have been. See A peek inside a Black Box - Harley Davidson Community

So based on what I have read & seen regarding late model 3 phase charging systems, I would be willing to bet that greater than 75% of the fried stators start out being a shorted rectifier within the voltage regulator which shortly thereafter takes out the stator. Once a simple rectifier shorts out, you only have minutes before the stator is toast. Even if the rectifier was to go open circuit rather than shorted, additional load will go to the other two phases. Especially when at rpm's in the 2500 range, you may have 25-30 amps being pumped directly into ground. No coil of 16 awg magnet wire is going to take that for any length of time.

I would bet that very few stators go bad all by themselves, leaving behind a perfectly good regulator. I am not saying it can't happen, because it can. But I do feel that most (>75%) of all stators that get fried because of a bad voltage regulator. So now the question really becomes "what shorts out the diodes or triacs (there are 6 of them) in the regulators to start this chain reaction?"

And to take it one step further, I would bet that many (maybe 40%) of all regulators will go bad because of either a weak worn out old battery or a voltage drop in the charging system wiring caused by a poor connection(s).

Remember that the charging system does not know the difference between a "run down battery" and a poor connection within the circuit. So the charging system works harder to overcome a loose connection,, constantly trying to charge up this "weak battery" that does not even exist. And the heat just builds and remains there all the time. The rectifier & stator will never get a break.

This is the classic mistake most people make when looking at a charging system voltage test. They place their meter across the battery, race the engine and read 13.80v and say it's OK. Or maybe they take it 1 step further than most and also read the voltage directly at the regulator and it reads 14.20v and they said "that's only a .40v difference so I'm OK". They are comparing that .40 volt drop against the 13.80 and saying "it's close enough".

A battery that is fully charged and not hooked up to a charger will have 12.70 volts across it's terminals. With a running engine, if the voltage across the battery was 14.70 volts, it would be said that the battery is close to (if not at) being overcharged. So that means the voltage difference between a battery not being charged AT ALL and a battery being OVERCHARGED is only 2.0 volts. Now look at that .40 volts of drop from the above example and compare it to 2 volts. That's a solid 20% of the entire charging system lost to a couple of bad connections. Every 1/10 of a volt counts and it adds up fast. Lose 1/10 here and 1/10 there and after you add them up, you may lose an easy 25% of your charging system just to a few connections.

Voltage drops will exist in both legs of the charging system so the 1/10's can add up twice as fast.

My opinion on the "chain of reaction" that takes place is that it starts with a worn out battery or combination of poor connections in the charging system along with a weak battery which forces the charging system into a constant overtime mode. Then with the constant overheating of the rectifiers to where 1 of the 6 finally lets go. The rectifiers then sinks the current from 1 phase of the 3 phase stator into ground. And now in a matter of minutes the entire mess is in meltdown.

Most of the above regarding the sequence of events is only my theory so delete as you wish.:)
 
That's an involved question with lots of pieces to the answer. Here are some facts and some theory behind the answer.
.. .. .. ... Most of the above regarding the sequence of events is only my theory so delete as you wish.:)

Well as usual, thank you for a most complete answer. And from what I saw I don't feel ANY of it was theory in that context, since every bit of it agrees with what I know of electicity. I've forgotten a lot but when I first got out of the Army I worked two years as an apprentice electrician. I also attended a 2 yr college instrumentation program on the G.I. Bill so I am not totally ingnorant when it comes to electrical subjects. However I moved on into the structural construction industry as a vocation and left the electrical many yrs ago.

But I am familar with voltage drops and the resulting amp rise, and I also understand that ANY amp rise is gonna be a heat rise. In fact if I remember correctly the term ampacity or amperage is actually a measurement (in physics) of heat, even though in electrical context it refers to amount current flow. So I can visualize what you say bout a weak battery causing increased amps (heat) and premature wear or failure of the diode rectifier.

Heck even I can't take the heat much after getting old. I have to stop 3 times for a rest just mowing my acre. My wife likes to jump in the pool to cool off. I like jumping on the Harley for a quick run up the road and back.
 
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