• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Anne Miller
  • Pearl Sutton
  • Nicole Alderman
stewards:
  • Mike Haasl
  • r ranson
  • paul wheaton
master gardeners:
  • jordan barton
  • John F Dean
  • Rob Lineberger
  • Carla Burke
  • Jay Angler
gardeners:
  • Greg Martin
  • Ash Jackson
  • Jordan Holland

Treadmill motor to charge batteries

 
gardener
Posts: 1339
Location: Westbridge, BC, Canada
351
building solar woodworking rocket stoves wood heat greening the desert
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Wondering if this motor from a treadmill that I scavenged recently is good for charging a 12V battery bank with a wind turbine.

Several things I've found out from my research:
1) What you are looking for is a motor that is rated for high DC voltage, low rpms and high current
2) Your homemade wind turbine, will likely produce around 500 rpm in average winds

So correct me if I'm wrong, but if this motor is rated to produce 2 amps at 4950 rpms, and I get 500 rpms as suggested above, would this mean I would get an output of about .2amps?

Doesn't seem worth the effort to build a turbine (other than for the fun of it) with this kind of power generation.
Any thoughts?   Thanks in advance.  
Treadmill-motor.JPG
[Thumbnail for Treadmill-motor.JPG]
 
gardener
Posts: 3869
Location: latitude 47 N.W. montana zone 6A
1107
cat pig rocket stoves
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Gerry;   I only see 2 H.P. mentioned on the data plate, not 2 amps?   Am I missing it ?
 
thomas rubino
gardener
Posts: 3869
Location: latitude 47 N.W. montana zone 6A
1107
cat pig rocket stoves
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
The way I read it you would be at or less 1/4 H.P. at 500 RPMs.
However with pulleys you might make the rpms higher at the motor than at the prop.
 
pollinator
Posts: 1577
Location: Victoria BC
229
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
It is labelled as 19.3A, 100V, nominal 2HP, at basically 5000rpm.


I have not built a wind turbine, but this seems like a good article:

https://sciencing.com/use-treadmill-motor-wind-generator-7704417.html

Based on the criteria described there, this doesn't look like a well suited motor, though.

Pulleys or gears could be tried, but seem like excess hassle unless it is impossible to source a more suitable motor.
 
Posts: 89
32
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
They put out wild DC.
The faster they go the higher the voltage.
You might want to run it through  a switching power supply, maybe a computer power supply,
to get it stable at 12 volts.
That might handle 4 amps.

On my peddle powered generator I had to use a 26" rim and a J6 belt to the small stock motor pully.
Not sure what RPM that gave me.
But it will run a blender.
Once upon a time, at the energy fair, a guy peddled one up to 250volts DC.
With a small wall cube plugged into it running a small DVD player  without a problem.
 
thomas rubino
gardener
Posts: 3869
Location: latitude 47 N.W. montana zone 6A
1107
cat pig rocket stoves
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Well Thank You D;
Once you told me it was plain as day... 100 volts , 19.3 amps at 5000 rpm. Must be getting old...  oh yeah , keep forgetting... I am old! (only the calendar says so ,not me)
 
thomas rubino
gardener
Posts: 3869
Location: latitude 47 N.W. montana zone 6A
1107
cat pig rocket stoves
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
So if we assume voltage and amperage drop equally .  
At 2500 rpm we would have 50 volts 9.65 amps
1250 rpm we would have 25 volts and 4.8 amps
625 rpm we are at 12.5 volts and 2.4 amps
312 rpm and we are at 6.25 volts and 1.2 amps...
Although it could be made to work in a pinch or with gearing.
At that output as D stated this motor isn't the best choice.
 
Gerry Parent
gardener
Posts: 1339
Location: Westbridge, BC, Canada
351
building solar woodworking rocket stoves wood heat greening the desert
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thank you everyone for your input. :) This is a pet project for my next trip down to Arizona in the desert but while I have some time here in the cold wintery days of Canada, I thought I'd look into it.

thomas rubino wrote:Gerry;   I only see 2 H.P. mentioned on the data plate, not 2 amps?   Am I missing it ?


Brain fart on my end.... that's why I need help...or maybe just glasses!

D Nikolls wrote:It is labelled as 19.3A, 100V, nominal 2HP, at basically 5000rpm.


Thank you for that....and while I'm learning, does V. Arm mean Voltage of Armature?  and A. Arm? Amperage of armature?
Will look at the link you sent me when I get some time. Adding gears or pulleys may work as suggested but to keep it simple, (as its my first build) I think I'll do without and see what I get.

craig howard wrote:They put out wild DC.
The faster they go the higher the voltage.
You might want to run it through  a switching power supply, maybe a computer power supply,
to get it stable at 12 volts.
That might handle 4 amps.


That sounds reasonable and doable for me. I'll look into it.
 
pollinator
Posts: 385
Location: Nomadic
35
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

craig howard wrote: They put out wild DC.
The faster they go the higher the voltage.
You might want to run it through  a switching power supply, maybe a computer power supply,
to get it stable at 12 volts.
That might handle 4 amps.

On my peddle powered generator I had to use a 26" rim and a J6 belt to the small stock motor pully.
Not sure what RPM that gave me.
But it will run a blender.
Once upon a time, at the energy fair, a guy peddled one up to 250volts DC.
With a small wall cube plugged into it running a small DVD player  without a problem.



  Craig,
Am I reading correctly that I can feed a switching power supply DC instead of AC and it will act as a DC to DC converter?? If this works there are some applications I can think of for my energy system.
I too have a treadmill motor I’ve not tried yet.
Thanks
 
craig howard
Posts: 89
32
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
That's right.
If you look on the back of the little wall cubes you will see they run on a large range of input voltages.
They aren't the old style with transformers anymore, they are called switching power supplies.
They don't actually say they run on DC but they do.

I bought one off ebay that said it was a switching power supply,... but it wasn't.
So be carefull.

Like I mentioned we had one pushing 250 volts DC in and 12 volts out running a small/portable DVD player.

Only things to look at are the outputs.
That will stay steady as long as the input doesn't fall below that.

4 amp ones are commonly used for computer supplies.
There are probably some that put out more watts/amps.

They are pretty efficient as well.
Often in the 95% range.
 
Jeremy Baker
pollinator
Posts: 385
Location: Nomadic
35
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I’d like to try a adjustable switch mode power supply but how do I determine the polarity if using DC not AC?. Would the “hot” side of the AC become the “positive” for DC use?
I see computer power supplies at the thrift store. This might be a inexpensive way to experiment. To run something like the treadmill motor would take a bigger power supply ?
Thanks
 
pollinator
Posts: 423
Location: Greybull WY north central WY zone 4 bordering on 3
86
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
How far are you running the wires from the turbine to the batteries?  A permanent magnet alternator so you can run it as 3 phase higher voltage back to the rectifier is far easier to handle.
gift
 
6 Ways To Keep Chickens - pdf download
will be released to subscribers in: soon!
reply
    Bookmark Topic Watch Topic
  • New Topic