How to charge battery bank via peddling bicycle? : LUSENET : TimeBomb 2000 (Y2000) : One Thread

It seems it should be possible to charge a bank of deep-cycle batteries by peddling a stationary bicycle or exercise machine. We have no idea how to do this, though. Or, how much pedalling = how much energy. Can anyone advise? Also, read somewhere that you can idle your car for 15 min. to charge a small bank of batteries, but no specifics on how to do it. Also, that it's a lot more fuel-efficient to use a small generator to charge battery bank, then run off the batteries till they need recharging. But again, no "how to." Thanks for any specific advicse.

-- Shivani Arjuna (, March 23, 1999


Interesting question!

I personally don't have any answers to this, but will be interested to hear the results. It seems that it would take an awful lot of pedaling though.

Got kids?

Mr. K
***would run out of breath***

-- Mr. Kennedy (run@full.speed), March 23, 1999.

other threads have covered this issue. and maybe check

-- j (, March 23, 1999.

I'll see if I can find the thread was hashed out a while back. From what I recall, you're going to have to do A LOT of pedaling (hours and hours) to charge that battery.

The energy produced while pedaling would only be enough to accommodate a light- bulb or, someone could read while you're huffing and puffing, and then you'd switch places (hey...IT'S YOUR TURN TO PEDAL).

-- Tim (, March 23, 1999.


This is done all over the world, really. You need an alternator, a bicycle and a frame with pulleys to connect the two together. If the alternator has a built in regulator you are much better off since you will not have to be concerned with overcharging the battery.

Check out this URL for a decent small engine rig:

Though it seems convenient to use an automobile to charge a battery it is VERY wasteful indeed. Most engines are 100 horsepower and only 1 horsepower or so is going into the alternator (limited by the belts and the size of the alternator).

If you can get a 'mountain bike' with 21 gears then you will have the gearing to drive a pedal power rig. It will take a pretty long time to charge because people power is much less than 'horse' power. Typically it takes about 2 'horsepower' to drive 1 kilowatt. So at 0.1 Kw (or 100 watts or 8.3 amps into a 12 volt battery) it will take approx 0.2 horse power to deliver that kind of charging rate into the battery. One horse power, I believe, is the power needed to lift 700# to a height of 1' above its previous position. So it would be like a 140# person pedalling up a slope of 1 foot every second (pretty steep). Luckily, alternators will produce power in a range and you should be able to charge pretty well at a lower rate (but for a longer period of time).

You might even be able to get an older bicycle and have a frame cut and welded to the host bike frame to hold the alternator for you. You would also need a way to keep the bike from moving as you an excersize stand for a bicycle.

It's a thought. And I like the idea of a bicycle to power a water pump as well. Leg muscles are much stronger and more durable than arm and shoulder muscles. Also reduces wear and tear on things like shoulder rotor cuffs and wrists, etc. There are reasons why our ancestors did and didn't do things the way they did..usually because they wanted to keep from injuring themselves/wearing themselves out.

-- David (ConnectingDots@Information.Net), March 23, 1999.

Yep, I have the Homepower Magazine CD Roms, and it takes a *lot* of energy to recharge a battery on a bicycle.

The GOOD thing, - you'll be *very* fit. The BAD thing - you'll find out what is really important really fast.

I have the parts to make a couple of these gizmos. I'll put them together next year if I need them.

Jolly likes bikes. But not THAT much.

-- Jollyprez (, March 23, 1999.

Go to library and checkout the book Pedal Power by Rodale Press, 1977, by James C. McCullagh. Provides numerous applications for bicycle power from running a grain mill to a portable washing machine constructed from a trash can oscillated by a stationary bike. Quite ingenious, worth a look!

-- John (, March 23, 1999.

Keep in mind that if you use pedal power to charge your batteries, what you're really doing is burning your beans and rice to create electricity, and inefficiently, at that. You'll have to eat more. If you've got plenty, fine.

Regarding idling your car to charge batteries - granted, it sounds inefficient. But it shouldn't be too difficult to rig two or more alternators to run off the idling engine. That should make it more efficient.

-- Ned (, March 23, 1999.

Shivani; Got a good question and project to make before Sept 99. I had thoughts about the same item, I plan to have an alternator mounted to the bolt for the seat post. instead of a "v" belt a hard rubber roller that has friction to the wheel, like a skate board wheel. Or use a gear set from another bike and attach it to the alternator,that way you can upgrade your gears to another speed above the bikes output. Let us know how your turns out,


-- Furie (, March 23, 1999.

Burns too many Calories! Go solar, let the sun do the work. No need to work up a big hunger and thirst. You will lose enough weight on the Y2K diet, don't peddle your supplies away.

-- Bill (, March 24, 1999.

Moderation questions? read the FAQ