Originally Posted by DiabloADV
OK -- I asked Euromotoelectrics...
The answer is non-specific. They had one customer that installed an Endurlast charging system in a Ducati, while also installing a Shorai at the same time. The customer had problems, so Euromotoelectric won't warranty their system with anything but conventional batteries. So, there seems to be nothing specific...simply a preventative measure on the vendor's part. Which I can understand...
correct me if I'm wrong... but here's the basics
all alternators rotates a magnet through or around the stator (HD). then uses a diode rectifier to convert the AC output to DC.
there's two different ways to generate the magnetic forces needed within a rotor. one type uses permanent magnets. other uses an electromagnet.
both types uses a voltage regulator. but they work entirely different. each has advantages and disadvantages.
permanent magnet alternators pretty much operate at full output all the time. excess current is shunted to ground in the form of heat. advantage is slightly higher efficiency. can still charge up battery in-spite of low RPM usage. disadvantage loss of HP generating excess current which ends up as heat. which can overheat area near voltage regulator.
electromagnet alternators varies the current delivered to the electromagnet rotor. voltage regulator works by changing current sent to electromagnetic rotor. disadvantage is this process uses 3-4 amps. output also varies with RPM. one could easily run down a battery if engine is not rev'd high enough. advantage is no wasted HP generating excess watts.
with all that out of the way... let's get to why I posted above..
what happens should a voltage regulator fail?
if a voltage regulator on electromagnet alternator should fail .. usual result is no output. very rarely does an internal short result in full output.
if a voltage regulator should fail on a permanent magnet alternator. output could continue at full output or fail altogether.
LiFePO4 motorcycle batteries are either not regulated and/or regulated at very low values after full charge is reached. this means failure of a voltage regulator on a permanent magnet is more likely to result in overcharging a LiFePO4 battery or any other battery to failure.
so if given a choice on Airheads of which high performance alternator to go with.... I'd pick the electromagnet alternator version every time. unfortunately on late model motorcycles you don't get a choice.