Instructables

How can I wire an alternator to a battery?

You know that show The Colony? In it they wire a car alternator to some batteries to make power. They showed how to do  all sorts of cool stuff on that show but they never elaborated on how exactly you go about doing it. I have an alternator and it has four pins. I'm assuming one's positive and one is negative but can anyone tell me what is what?

pvan heerden11 months ago
The "end idea" would be something like this.. getting to turn the alternator.. (by means which you ever prefer).. get to wire it correctly and safely to a battery.. then connecting it to an invertor.. connecting a multi plug and connecting one or more electric appliances for usage..

BUT.. for me that has NOT done anything of this nature in a LONG time.. HOW to do JUST THIS successfully is my question..? without making it sound like rocket science. As i go along and get to finish the first attempt.. i'll be able to improve on it.
orksecurity4 years ago
Nothing is "making" power, just converting it from one form to another.

An automobile alternator is essentially an AC generator. If you spin it fast enough, long enough, you can put the output through rectifying and regulating circuitry and use the output to charge up a battery. The simplest solution, of course, is to use the car's own existing circuitry to charge the car battery.
The "end idea" would be something like this.. getting to turn the alternator.. (by means which you ever prefer).. get to wire it correctly and safely to a battery.. then connecting it to an invertor.. connecting a multi plug and connecting one or more electric appliances for usage..

BUT.. for me that has NOT done anything of this nature in a LONG time.. HOW to do JUST THIS successfully is my question..? without making it sound like rocket science. As i go along and get to finish the first attempt.. i'll be able to improve on it.
lasersage4 years ago
ork, don't be a pedant, you're not really answering the question are you?

Generally alternators produce three phase. Old dynamos work like motors in reverse with just a positive and negative but are very inefficient. You find them on ancient 6V machines.

Nearly everything these days uses proper alternators with three phases, which means you require a rectifier and you might want to consider a regulator.
The rectifier has a bunch of diodes, at least 3, which take the three phases and convert them into something useful. You get like three displaced sine waves of 8V or so I think. When rectified and overlapped these give you the 13V needed to keep your 12V battery charged.
The rectifier is the key here. All vehicles with an alternator have one, even motorbikes.

The regulator is a separate issue. It wastes off excess energy as heat through a resistor, it switches in when the engine is revving hard making lots of power but you've got a well charged battery and aren't running, lights, wipers, radio, etc. Otherwise you risk overcharging your battery. This may not be an issue for you though depending what you're driving the alternator with.

A quick google search for alternator rectifier circuit turned up this
http://www.allaboutcircuits.com/vol_6/chpt_4/8.html
the schematics say it all
Funk_D (author)  lasersage4 years ago
A lot of info here! Thank you! I looked into it some more on google and found this site http://www.theepicenter.com/tow082099.html and they actually have pictures and everything. Both you and Re-design gave me some better words to google and I found it. lol. So thank you both!
Re-design4 years ago
Remember that not everything you see on TV is true, believable or even possible.

Go to this site and look at the second diagram down. That's all it takes to get a basic alternator wired.  Not shown in the diagram is something to turn the alternator.  Most alternators won't even turn on until about 3000 rpm.  It's the way they are built.

Most alternators have the rectifiers built in.  I'll bet you will have a hard time finding one that isn't built in.  But I've only handled 5-6 different alternators in the last 10 years so check.

Alternators have to have a battery to start the charging since they have no permanent magnets like a generator.

G00gle, "one wire alternator" or "simple alternator diagram" etc. to find out more information.

Good luck.


Koosie4 years ago
Well, not all alternators have the same wiring setup.  If you can get the make/model and/or serial number, you should be able to Google the info needed.

Then, once it's connected, you just need to rig something up to run the alternator.  Like a wind-mill or a small motor.  Personally, I like the idea of the wind-mill, but that's just me.