How To

1. Get an alternator from a junkyard (or pay for a new one on ebay, rockauto.com, etc.)

(If anyone has pictures/model numbers/car models and years, please contribute here.) Phantom 48 used a GM alternator. Phantom ICT uses a bigger one.

1. Remove the regulator. (Unbolt)
2. Solder some RC style bullet connectors on to the three windings.
3. Solder wires onto the contacts for the brushes to drive the field windings.
4. Isolate the brushes from the case with a nylon washer.
5. Get a controller.1500W
6. Get a field drive (Constant Current). DC-DC Buck Converter Step Down Regulator 60V 48V 36V 24V 12V to 19V 14V 9V 6V 3V
7. Carefully set the field to about 3-4A with a screwdriver. (Start at lowest voltage/current and carefully work your way up with both a current meter and voltage meter to monitor your progress)
8. Drive!

Extra credit:

• Field weakening.

Someone add notes here, because I've never actually done it on a car with any success. You basically have it run less current to the field once you hit top speed, and then you can go faster.

• Field strengthening. Some cars do this. They have a button that increases the current to the field. The button basically puts more current into the field so that you have more torque to start from a stop (at the start of the race, etc.

(David Ortiz-Grob) First stop: get that 1500w motor controller that’s like $34 (Jared McNeil)

this one: https://www.ebay.com/.../48V-DC-1500W.../252876629480… EBAY.COM 48V DC 1500W Brushless Motor Controller For E-bike Scooter…

(Craig Byrne) Is there an agreed upon field winding voltage range yet? Or if it needs to be dynamic depending on throttle? (Jared McNeil) the way i understand it is that field current is more important than field voltage, and that it should be right around 4 Amps continually from startup all the way up until your max speed. THEN it is optionally dynamic (but only in the lessening direction) to further your top-end.

Jared McNeil we ran with a 12V4A field coil on a bench test with success Iacona Andrew What do you use to make the field

Craig Byrne Basically, take the cap off an alternator and remove the diode pack., you'll either find 3 wires of 6 wires on the outer windings. If it's 6 make them into 3 consecutive pairs. Then take apart the part where the brushes contact the “commutator” you'll need to apply voltage to this to make the the the shaft an electromagnet. This replaces the permanent magnet in other brushless motors.

Jared McNeil this isn't the best video in the world but it goes over a bit about how to make those changes: https://www.youtube.com/watch?v=IKqy3rRWJQE

YOUTUBE.COM Converting a Car Alternator into a Go Kart Motor

Iacona Andrew I watched it seems to skip a lot of things

Jared McNeil yeah there's some more content i found about it when i was researching about how to do it also and idk if i can find it again

Iacona Andrew Also does the size matter? Car, truck etc

David Ortiz-Grob David Ortiz-Grob Bigger is better obvs but there’s no straightforward way to convert the rated generation voltage and current into usable motor power

(Not entirely true. The big alternators on Phantom ICT seem to draw a lot of current just spinning themselves with no load. Whereas the smaller ones on Phantom 48 seem to have a lower current draw. This matters due to the fuse limit.)

Murray Hersh Murray Hersh Just as a heads up on the $30 eBay controller. It's generally a great controller however it does seem to be limited in terms of maximum output frequency.

We could figure out how well it will work if we know the kv of the alternator (under various field currents) as well as the number of poles.

IaconaAndrew What would be the better speed controller for this project? On a budget of course

Murray Hersh Murray Hersh IaconaAndrew The eBay controller actually should work pretty well especially for a budget build. I'm generally impressed by the controller, especially for $30. It's biggest limitation is output frequency, however with the data Marshall Scholz posted a…See More

Murray Hersh Murray Hersh Okay here is some data courtesy of Marshall Scholz:

All duty cycle at 95%

Actual voltage is correct. Batt was discharged

Rotor current: 0.93a Rotor watt: 2w Vbat: 45.7v Ibat: 4.52 Imotor: 4.76 Watt@noLoad: 207w erpm@no load: 38338.0

Rotor current: 1.5a Rotor watt: 2.9×1.5 = 4.35w Vbat: 45.7v Ibat: 4.74 Imotor: 4.99 Watt@noLoad: 216w erpm@no load: 27448.0

Rotor current: 2.0a Rotor watt: 3.9×2.0=7.8 w Vbat: 45.7v Ibat: 5.05 Imotor: 5.31 Watt@noLoad: 230w erpm@no load: 23005.0

Rotor current: 3.0a Rotor watt: 5.9×3.0=17.7w Vbat: 45.7v Ibat: 5.85 Imotor: 6.15 Watt@noLoad: 267w erpm@no load: 19293.0

In short the output frequency is a little high at the low field current side of things, but should work under the higher field current values with the standard eBay “1500w” controller. I would recommend sensorless honestly.

Marshall Scholz A 100+a alternator is probably ideal. I Use one of these https://ebay.com/itm/172787419292?ul_noapp=true DC-DC Buck Converter Step Down Regulator 60V 48V 36V 24V 12V to 19V 14V 9V 6V 3V

To supply my rotor current. Since it is resistive and doesn't recieve a changing feild you. Can use cc or cv to power it I use 3a when I'm not dynamically controlling the feild on my alternator. I suggest having an easy to reach pot that will control feild current if you don't do it dynamically. It should adjust between 1-5a

Andrew Davis FYI. Wear safety glasses. I got one of these and was adjusting the output voltage an it blew the capacitors. Albeit, I was adjusting the regulator no load, which i don't think should matter, but whatever safety first!

IaconaAndrew The one question that jury still seems to be out on is what alterntor will work best? Truck, SUV, car ? I ve learned bigger is not always better

Pole Guy It seems the GM alternators on Phantom 48 (which are smaller) seem to draw less current at full speed. That's good. The bigger ones used on Phantom ICT draw more current at high speed. They work, but maybe not so good.

Also, belt drive works great, but maybe not so well with sensorless controllers, because there is no slop (from a chain) so the motor controller has trouble starting with the full load applied immediately as it can't figure out it's position without drawing too much current.

This is not necessary if you're running sensorless or use a shaft mounted magnet and a magnetic sensor (ala Phantom 48 and Phantom ICT)

Grayslake Garage - CartastropheLike Page July 20, 2015 · I just went through the process of installing Halls in the MK III alternator. Since a lot of people in KC asked about installing Hall sensors, I thought I would share a photo guide. I should do an instructable, but if I never get a round to it, then the info never gets out. So, here ya go.

1. Step 1: Grind out some “Hall holes™” in the stator with a Dremel and a carbide burr. Try to find slots that don't have windings to close to the surface. If you can't, just get another alternator (or the front half and stator from one) they are like $10. On the MK III (pictured) I have a Franken-nator because I had a front half that had room for sensors and a different back half that had good brushes and a new bearing.

Jon Halverson Try not to short the laminations during this process. There may be a way to etch back a bit with some salt and vinegar. Manage Like · Reply · 3y Grayslake Garage - Cartastrophe Grayslake Garage - Cartastrophe Yeah, good point. I was worried about that the first time I did this but nothing bad “seemed” to happen. Maybe we'd be twice as fast if I wasn't always creating wild eddy currents in or motors ;) Manage Like · Reply · 3y Jon Halverson Jon Halverson likely just a little extra heat. probably not a big deal, but this is racing!

1. Step 2: Add some small “whiskers” to the sensors. I use some enamel coated wire.
2. Step 3: Insulate solder connections (I used a little Kapton tape, but other things work) and glue into place with some super glue.
3. Step 4: Slather the things in “red insulating varnish” (search McMaster).
4. Step 5: Join the 3 VDD wires together. Join the 3 GND wires together. Wire and shrink tube those and the 3 OUT leads to the wires that will exit the alternator. Tidy it all up and put the thing back together.