[SIZE=4]@MaxHeadRoom[/SIZE]
I do not want a higher voltage, I want 14.5 V regulated charging the battery, but with lower current because the effort rotating the alternator is very high. I want a lower current INPUT for a lower current OUTPUT at same voltage output.
Think is possible?
Thank you!

 

LOL, shouting won’t help. Just tag him as I’ve just tagged you, @allaidept

 

NEWS. Surprise. My alternator does NOT have a built in regulator. So I must reconsider all my work. I will test your information using a regulator and send feedback. Thank you.

It don't have built in reg.
How old is it and what's it off?
Look for an alternator from a small vehicle that's not got a lot of electrical consumers, no electric windows, no air con, no high powered audio, just the basics, something of a small 90's Jap vehicle will do

 

This one is only 40Ah. I dont know something smaller

 

This one is only 40Ah. I dont know something smaller

That would be 40A not Ah, which is a battery rating.
If you want the output voltage/charge rate to be adjustable, you could add a pot to control the current to the alternator rotor winding.

Can you measure the rotor winding resistance?

 

That would be 40A not Ah, which is a battery rating.
If you want the output voltage/charge rate to be adjustable, you could add a pot to control the current to the alternator rotor winding.

Can you measure the rotor winding resistance?

6 ohm is the excitation (rotor, field) coil resistance.

 

A simple regulator can be built with a LM311 comparator, if there is no residual at start, you would need a initial excitation voltage until generation starts.
This simple regulator can be adjusted by pot if necessary.
Max.