DIY The AlternatorGenerator by David Poz

[Bud Martin]

Very interesting video, especially using Victrom MPPT as the charge controller fed from the output of the alternator (215A)

 

[Rednecktek]

Still requiring a $1000 MPPT controller really nixes the whole project for most people. For that kind of money you can get a gas generator and a 48v charger and still have lunch money left over.

 

[Bud Martin]

He is just using what he has at hand and as proof of concept, it does not have to be Victron.

 

[Rednecktek]

Yeah, I was watching it in the other window as I posted. At 90v that's totally in range of a 150v, or maybe a 100v MPPT controller that isn't blue.

 

[toms]

I didn’t watch the clip, I’ll watch the one where he draws a couple of hundred amps out of a typical car alternator for a few hours twice a week for five years.

 

[Deveak]

I’m surprised the magic smoke didn’t escape. I remember asking an engineer about this at midnite and he explicitly told me it’s a bad idea. Maybe it’s the extra high voltage ceiling of that controller.

So the basic gist I am getting is with the stock regulator removed and x current and voltage supplied to the field windings the voltage is pretty much semi controlled and it can be ran open circuit?

My grandpa told me back in the day they had a circuit/product that would get you 120 volts for light bulbs from car alternators.

Maybe a fangposun knock off for a cheaper option? No idea how to get one these days.

 

[rhino]

it should be a lot more efficient than an AC generator charging a battery through your inverter/charger.

 

[copec]

It's generally a bad idea to ignorantly hook up a charge controller to an alternator/generator because the short circuit amps on an alternator/generator can be many times that of what it is rated for, unlike PV. Also, it has inductance that can spike many times the voltage. Both of those things could easily result in a current or voltage way outside spec of components on the input stage of a charge controller.

The ideal would be to have a charge controller measure the effective output of an alternator/generator into a battery, and vary the exciter field current to reach the constant current or constant voltage part of a charge curve. This probably wouldn't be too hard to put a prototypish something together with all these off the shelf embedded boards these days.

 

[rhino]

There is a large capacitor used as well.