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Hi all:

I have a couple of questions on a motorcycles alternator:

1) What is the RPM range in a motorcycle (say the SV650) for its alternator to provide the maximum amount of current to the system?

2) Is there a certain RPM range (not zero) where the alternator seizes to provide current to the system? If so, why does this happen?

Thanks dudes.
Your help is very much appreciated
 

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motorcycles use stators, not alternators. I don't know #1, but there would be no rpm range where the stator doesn't provide current. The lower the rpm, the less current obviously.
 

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Most all modern bikes use a Three Phase Permenent Magnet charging system. Big magnet flying around a set of woud up wire. That produces AC voltage. That then passes through a series of diodes in which convert the AC signal into DC.

A few bikes (Bandit 1200, R series BMWs, for example) use an alternator, or a Three Phase Electro Magnet system (Center Tap is another name). The only difference here it that instead of just a regular magnet, this one's magnetic field is varied, which controls the amount of AC voltage produced.

Permenent magnet is a total loss system, extra voltage is just shunted back to ground. While Electro magnet systems only produce what they need.

Either system (in working condition) will produce voltage at any rpm. For instance, Breakeven speed is the rpm in which the charging system is producing enough voltage to accomdate the needs of the bike, but not any extra to "charge".

If you had a voltmeter hooked up (in series) to a battery while the bike was idling and the meter read "0 amps", then that is right at break even.

If in the same scenrio, the meter read "-1 amps", That means the charging system isnt producing enough voltage at idle to keep the battery at a steady voltage. The bike would evenly die if left idling long enough.

Same thing again but "+1 amps" at idle means that the charging system is producing what the bike is using, plus some.

In my limited amount of experience, Ive found that most charging system provide peak output anywhere from 3k to 6k rpms. Ive even seen some that will drop back down in the higher rpm ranges.

Lol, not sure that answered any of your questions, but hey, maybe you learned something lol.
 

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motorcycles use stators, not alternators. I don't know #1, but there would be no rpm range where the stator doesn't provide current. The lower the rpm, the less current obviously.
it's still an alternator, the stator is only part of it, the alternator (stator & permenent magnets) produce 3 phase alternating current that is converted to DC by the RR
 
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