what voltage do you want to run at?
24? Â 48? Â other?
my prototype 24 volt nominal will do 2.9 kwatts all day long at 28.8vdc and 100amps
and 15 minutes at 28.8 and 130amps
my prototype 48 volt nominal will do 57.6 at 75 amps in early testing which works out to ~4 kwatt
and i am fairly certain it will do 5 kwatts continuous by the time i work out a few kinks
the 24 volt version will match any ST head in efficiency, and the 48 volt version has done a couple percent
better in testing so far...
more work to be done.
either of these units could be had for a small fraction of what polar wants for theirs
btw, the 24 volt version is 16 pole, and the 48 volt is a 12 pole unit.
neither is a pm head and either can be controlled with a balmar for 3 step charging control and programmable
for any battery technology.
i studied polar's alternators about 10 years ago, nice stuff, but very expensive
and to get accurate control for battery charging is not as easy as one might think
one would have to have a fully functioning electronic governor and integrate it with another microcontroller
to take full control of battery charging.
not a saturday afternoon project by any means.
unless of course you want to babysit the throttle to manage the voltage,, Â but then again
you cannot easily manage the amps via rpm of the engine.
the aircore homebuilt pm alternators such as the otherpower boys build are very interesting, and because you build
it yourself they are easily repaired,, that has a lot going for it in my opinion. i am not convinced that an aircore is as efficient
as a battery charger driven by an engine,, but then again i have not seen really good and accurate test results using one either.
bottom line?
there are a lot of options i would explore before i parted with 2-4 grand for a pm head from polar or anyone for that matter.
btw, i am not a big fan of hydrogen appliances pm alternators, although there are those that seem to really like them.
bob g