The next word you are looking for is Armature.

Go ahead Harley Davidson and tell them what an Armature is and why that is the difference between "generator" and "alternator".

Harley Davidson: "The third thing is that the rectifier/regulator is a shunt type. The stator puts out full power all the time and the regulator shunts the excess to ground to regulate the voltage at ~14.4VDC. It requires the battery to be connected or its internal circuitry shuts it off to prevent the variable shunt resistor from burning out."

Right there is why you should go to the "Compu-Fire" regulator, instead of going to ground it shuts down the alternator system, thus unloading the alternator and increasing power and fuel mileage.

Best explained subject ever on this forum.

So to answer the OP: The battery runs the bike and the alternator keeps the battery charged.

 

So the importance here is that without a good ground from the regulator to the chassis and the chassis to the battery ( which is nothing but a storage unit) it will

1) not recharge the battery properly

2) Overheat the regulator and cause it shut down because it will not properly shunt the excessive voltage to ground. (which actually charges the battery)

3) And now that the regulator is not working it has no way to dissipate the a/c voltage from the pm alternator causing it to also over heat and eventually short the windings.

This is how I understand it but am I right?

 

This. Most cars run off the charging system, the battery is just there for initial starter power, bikes are basically opposite.

Some really knowledge in above posts!

 

The generators used in the Knuckleheads, Pans and Shovels for many many years are backwards from an alternator. An alternator has a stationary stator winding with a rotating magnetic field. The generator has a stationary field winding with a rotating armature where the windings in the armature cut the lines line of magnetic force and create current in the armature winding.

Generators, just like alternators, produce AC power except for one important difference. Alternators use solid state diodes to rectify the AC to DC. A generator has an ingenious mechanical rectifier in the form of brushes and commutator. Generators are no longer used because the brushes wear out, the commutator wears out and they are not as electrically efficient as alternators are, nor can they be run submerged in oil like permanent magnet alternators can.

The Compufire series-regulators are indeed quite nice because they reduce the load on the stator with FET's (Field Effect Transistors) that only conduct for the required part of the AC cycle instead of shunting to ground like SCR regulators do. A new Compufire three-phase stator, rotor and regulator is laying on my workbench as I type this and is one of the winter upgrades being done to my '86 FLHT. It upgrades the original 22A single phase unit to 40A three-phase - got it from Dennis Kirk for $360. My wife and I do mostly long distance touring miles on the '86 and we want to be able to run our Widder electric vests for cold weather riding, as we do most of our touring in Canada. The old 22A just can't do it, as it barely keeps up with the driving lights on at cruise rpm.

Anyway, that's the best I can explain it in as simple terms as possible. I worked as an engineer for Cummins Power Generation for 19 years and sometimes have the tendency to try to explain things in terms that make no sense. So would be worthless to anybody trying to understand their changing system. The charging systems in our Harley's are very simple, proven and quite reliable albeit with a few limitations.

 

You guys are going to laugh about why I posted this topic.

I ordered a very expensive overkill battery for my bike on October 30, still have not received it, no tracking information provided, etc. It's a long sad frustrating story that is still not resolved and I am out a good chunk of money and I don't know if the battery will show up tomorrow, next week, next month, or never. Very frustrating to say the least because this battery costs way more than a regular battery.

 

Nothing to laugh about there.
What kind and who did you order it from?

 

Thanks HD that explains it good.

Now we have to find out who screwed Prot so we can avoid them.

 

I am kind of wanting to see how this ends up. Maybe there is something wrong with their ordering system. I will post the final outcome and how it was handled.

If it ever gets here, it is a 720 cranking amp battery. 2 gauge Sumax cables from JP cycles have already arrived.

 

Harley-Davidson thank you for taking the time to explain all of this! I have learned something today thanks to you...well, I'm not precisely clear on all of it but you peaked my curiously to do a bit more digging on the subject.

 

Harley-Davidson is one of the smartest guys here and he certainly knows how to explain things. he is an outstanding addition to this forum. he really racks up the miles too.