Using an old car alternator to generate electricity...

[RebelRider.Mike]

I made a video of my alternator tear-down. Not gonna be a cinematographer any time soon, but here it is.
[youtube]o-pqzrTAvCo[/youtube]

 

[billvon]

If I pursue the project further, I'll add an On/Off switch, variable resistor (for the field coil) and a V/A meter to the handlebar. A nicer looking platform with a battery mount would be good too.

Recommendation - keep field as low current as possible (more efficient) and use the bike's gearing to get appropriate voltage out.

 

[markz]

You should hook the alternator up to a bicycle wheel on an ebike and see what your returns are, if you have an inverter then all you'd need is 120Vac and 4A output, so 500W inverter, and a digital multi meter to see what the net loss is.

 

[RebelRider.Mike]

Thanks for the suggestions!

I've made no progress on the "power bike" since my last post. My old car's carburetor bit the dust and I'm elbow deep in rebuilding it at the moment. But I did finally finish edditing the second video I made reassembling the alternator.
[youtube]JxQDqD6z5Jo[/youtube]

I hope to make at least one more to show the final (or working) product.

 

[ACDC_comeback]

A power inverter is definitely the way to go. I built my own generator with an 8hp engine, a 180 amp 12v truck alternator, and a 3000w inverter. I also have a deep cycle battery so I can use some power when the engine isn't running, and I have electric start with a remote. Best generator ever! It will surge 6,000w for 5 seconds, which is WAY more than a 3kw standard generator can surge. I can also use it to jump start/recharge anything 12v.

I did, however, spend a ton of money to build this thing. I could have bought a generator off the shelf for cheaper...but I like mine better.

 

[amberwolf]

Wierd; it can do all that but can't charge a dead battery?

https://endless-sphere.com/forums/viewtopic.php?f=14&t=98937

 

[JJBuddas]

Hi guys I’m new to this in forums I live in Ponce P.R. Where experiencing a lot of quakes and losing power a lo I’m trying to build a system to power my cpap machine for my sleep apnea I attached a 12v dc motor to a chevy one wire self exited 220 amp alternator and if I connect each one to a different battery once I connect the alternator it slows the motor wich is normal and it charge 14.8V but one I connect al together to 3 car batteries in line once I turn the alternator on it Slows the motor a lot and it stops charging to 9 or 10v. Dont know What’s the problem I’m planing on using a 2000 watts inverter from harbor freight so I could power my cpap,fan,and tv if someone could help me I’ll appreciated I’m not an expert but got the idea and thought could work thanks

 

[amberwolf]

let me make sure i have this right.

you're using batteries to power an motor that spins an alternator that powers an inverter?

or are you using batteries to power a motor that spins an alternator to charge the batteries?

which of those, if either, is correct?

if neither of those is right, please specify exactly how it is all hooked up, and what the intent is.

then we can help you figure out the problem, and fix it, or find a better way.

 

[billvon]

Dont know What’s the problem

The problem is that you are trying to build a perpetual motion machine and those don't work.

 

[RebelRider.Mike]

What is powering the DC motor? If you already have electrical power for the motor, you should use that to run your CPAP and things. The only reason to use an alternator to make electrical power is if you have some kind of rotational power source, like a gasoline engine, to turn the alternator.

The more Amps you pull from the alternator, the harder it will be to spin. If it's not able to spin fast enough under the load, the Volts will start to drop too. I think your best bet is to charge up the batteries with either a generator or solar panels.