Living Car Free - Anyone converted their bike trainer/stand to generate power?

Has anyone here converted a bike stand/trainer to be able to generate electricity? How did you do it? What did it cost? How much energy/output are you able to geenrate?

Don't try to convert a trainer, just get a permanent magnet DC motor ($10 online, I forget where...I'll find it for you later) and bolt a chainring to the flywheel. Then you just run the standard system you'd use on any kind of generator to charge a battery. I'm busy now, but I'll get you some info tomorrow. It's not hard to do, and the only expensive part is the battery pack.

Don't try to convert a trainer, just get a permanent magnet DC motor ($10 online, I forget where...I'll find it for you later) and bolt a chainring to the flywheel. Then you just run the standard system you'd use on any kind of generator to charge a battery. I'm busy now, but I'll get you some info tomorrow. It's not hard to do, and the only expensive part is the battery pack.

Thanks! I can't wait. :)

the Zombie Survival Guide mentioned bicycle generators, so I imagine you can buy them prebuilt. Check eBay?

Yeah, just google "Bike Generator", you get plenty of results.

Here's one driven off of the rear tire:

http://www.scienceshareware.com/build-your-own-generator-bike-trainer-stand.htm

You'll have a much greater power output with a motor that is driven directly by the chain(cog bolted to the flywheel) than you will with something being spun by friction with the rear tire. I've been super busy, but I promise I'll get you full details soon.

Don't try to convert a trainer, just get a permanent magnet DC motor ($10 online, I forget where...I'll find it for you later) and bolt a chainring to the flywheel. Then you just run the standard system you'd use on any kind of generator to charge a battery. I'm busy now, but I'll get you some info tomorrow. It's not hard to do, and the only expensive part is the battery pack.

Any chance I could get the info? :) Thanks!

If you are lucky, you can generate about 100 Watts average while sitting on your trainer at home for a hour or so. But, let's say you can stick it out and pedal the trainer for 10 hours. If so, you will generate 100- Watt-hours, or 1 Kw-Hr. How much do you pay for a KW-Hr? I'll bet it's less than 25 cents, but let's assume you get a really bad deal and pay $1 for it. 10 hours of work to save $1 (or less) is pretty poor return on your investment. It also shows just how much of a bargain electricity is given the amount of work it can perform.

So, unless you live in the third world, or suffer from rolling blackouts, driving a generator off a bike is a waste of time.

Any chance I could get the info? :) Thanks!

Argh! I totally forgot. PM me so it sends me an email, I check that much more often than this forum. The above post is correct about the fact that the price per kilowatt hour versus your time invested pedalling yields a poor return, especially on your $ investment, but I wouldn't call it a waste of time if it's something you'd like to do.

If you are lucky, you can generate about 100 Watts average while sitting on your trainer at home for a hour or so. But, let's say you can stick it out and pedal the trainer for 10 hours. If so, you will generate 100- Watt-hours, or 1 Kw-Hr. How much do you pay for a KW-Hr? I'll bet it's less than 25 cents, but let's assume you get a really bad deal and pay $1 for it. 10 hours of work to save $1 (or less) is pretty poor return on your investment. It also shows just how much of a bargain electricity is given the amount of work it can perform.

So, unless you live in the third world, or suffer from rolling blackouts, driving a generator off a bike is a waste of time.

Not if you were going to ride your trainer anyway. It'll probably come in handy during blackouts.

I'd see this very practical for people planning on making long trips on their bikes--like touring. For myself, I'm thinking of taking a trip from Chattanooga down to the Florida Keys towards the summer and this would solve the problem of how I would power my laptop during the trip. I had been considering solar power (they have a card you can plug up to your laptop) but this would be much better overall, it seems.

I'd see this very practical for people planning on making long trips on their bikes--like touring. For myself, I'm thinking of taking a trip from Chattanooga down to the Florida Keys towards the summer and this would solve the problem of how I would power my laptop during the trip. I had been considering solar power (they have a card you can plug up to your laptop) but this would be much better overall, it seems.

Yeah except then you have to carry a trainer with you.

the Zombie Survival Guide mentioned bicycle generators, so I imagine you can buy them prebuilt. Check eBay?
You didn't believe like...everything you read in the Zombie Survival Guide, did you?

Yeah except then you have to carry a trainer with you.

This is the first time I've heard of this, really. Isn't there just something I could attach to my bike and then have a battery in my bike trailer? I'd think it would be fairly small.

This is the first time I've heard of this, really. Isn't there just something I could attach to my bike and then have a battery in my bike trailer? I'd think it would be fairly small.

You could get a generator hub but they only output 3 watts. It'd be so much simpler to just look for an outlet for your laptop power supply. Campgrounds, restaurants, libraries, and certainly motels, all will have outlets scattered about. It's not hard to find one if you look around.

Better still, is to leave the laptop at home.

You could get a generator hub but they only output 3 watts. It'd be so much simpler to just look for an outlet for your laptop power supply. Campgrounds, restaurants, libraries, and certainly motels, all will have outlets scattered about. It's not hard to find one if you look around.

Better still, is to leave the laptop at home.
That's right. You can check E-mail or blog from just about any public library--free.

Again, thanks guys. The library does sound like the best option...as I rarely actually need my laptop to create things. And anything I want to do on my site, I could probably just edit directly on the server.

http://www.scienceshareware.com/how-to-measure-DC-current.htm

http://www.scienceshareware.com/bike_gen.htm

Realisticly, you could pedal all day and only generate ten cents worth of power.

But it would come in handy in a blackout.

Some deep disharge batteries, a 12 volt to 120 volt inverter, and some photovoltaics (solar panels) would be first on my list.

I would use solar panels to charge my electric moped. I use the grid to charge my electric bike now. The electric bicycle has a generator mode, but I have yet to make the 5 LED power display move up a notch by pedalling.

http://www.scienceshareware.com/how-to-measure-DC-current.htm

http://www.scienceshareware.com/bike_gen.htm

Realisticly, you could pedal all day and only generate ten cents worth of power.

But it would come in handy in a blackout.

Some deep disharge batteries, a 12 volt to 120 volt inverter, and some photovoltaics (solar panels) would be first on my list.

I would use solar panels to charge my electric moped. I use the grid to charge my electric bike now. The electric bicycle has a generator mode, but I have yet to make the 5 LED power display move up a notch by pedalling.

So how many square feet of solar panels does it take to charge your moped in between uses? Keep in mind that you can't use it during the day if it's charging.

Also, keep in mind that charging a lead acid battery is only about 70% efficient, meaning that it requires about 142 watt-hours for every 100 watt-hours you store in the battery. Then there are is the inefficiency of the inverter. At best, you will lose 10% of your stored power in the inverter. So, for 142 watt-hours on the bike, you'll get less than 90 watt-hours delivered to a load. That's not going to be very useful.

For lighting and to power radios, you would be better served using small battery operated LED flashlights and a walkman-type of radio with a couple sets of batteries kept aside for emergency use. If you have need for more power, then consider keeping a marine battery or two on a trickle charger so it will be fully charged when you need it. A typical deep discharge battery holds about a kilowatt-hour of power. It would realistically take you days to generate that much power on a bike. By then, the lights should be back on.

Again, thanks guys. The library does sound like the best option...as I rarely actually need my laptop to create things. And anything I want to do on my site, I could probably just edit directly on the server.

Uh, yes/no. Don;t send ANYTHING that you want to keep secure/secret from a public computer. And if you're logging on to a network that you don't control, be very careful about data you send/receive. Likely they're able to listen in on it, so you better trust them.

Trying to understand watt output and storing it in a battery here...

So, let's say I could put out 1000 watts for 5 seconds (as a pro cyclist ;)), would that fill the battery as much as putting out 200 watts for 25 seconds straight?

Is there some limit as to how much can go across the line to the battery?

Is the percentage of watts actually transferred to the battery static across all watt ranges?

I'd see this very practical for people planning on making long trips on their bikes--like touring. For myself, I'm thinking of taking a trip from Chattanooga down to the Florida Keys towards the summer and this would solve the problem of how I would power my laptop during the trip. I had been considering solar power (they have a card you can plug up to your laptop) but this would be much better overall, it seems.

Was wondering how your road trip worked out. Did you add a charger system and battery. A couple years late but some positives if you skipped adding charger system
1) Most Laptops use only 20 watts
2) Battery you are charging on long road trip is when laptop not being used.
3) Downhill easy charging :-)

Solar Power would probably be easier if you are towing a bike trailer.
Put the panel on top of trailer.

Trying to understand watt output and storing it in a battery here...

So, let's say I could put out 1000 watts for 5 seconds (as a pro cyclist ;)), would that fill the battery as much as putting out 200 watts for 25 seconds straight?

Is there some limit as to how much can go across the line to the battery?

Is the percentage of watts actually transferred to the battery static across all watt ranges?

A good approximate model for a battery is a voltage source in series with the internal resistance of the battery. As current flows through the battery, the internal resistance dissipates power and generates heat. The maximum current is limited by how much power the battery can dissipate without exploding or otherwise being damaged.

Power supplied by (or to) the battery is approximately proportional to the current, while dissipation is proportional to the square of the current. Because of this, low currents tend to result in less energy being lost to power dissipation--practicing your sprinting on the trainer is probably not quite as efficient as a slower, steady charge if you do the same amount of work in both cases.

You could get a generator hub but they only output 3 watts. It'd be so much simpler to just look for an outlet for your laptop power supply. Campgrounds, restaurants, libraries, and certainly motels, all will have outlets scattered about. It's not hard to find one if you look around.

Better still, is to leave the laptop at home.
I think its still nice to be able to generate some electricity whether through a hub or solar panel while on tour. There's also recharging a cell phone battery, and recharging a digital camera battery. If you are camping and not eating in restaurants, its difficult to get to recharge these items. I'm not going to leave a digital camera plugged into a publicly accessible washroom outlet for a few hours. If I'm not in a campground at all...

Or one can buy this http://www.dahon.com/accessories/2010/biologic-reecharge.

The best solution Ive heard of is adding a large diameter/mass flywheel in order to balance out any fluctuation in cadence and allow a better power output after utilizing the bikes gearing. as others have stated the battery pack is the most expensive part, and getting the right batteries can be pretty important in some of these systems.

It also shows just how much of a bargain electricity is given the amount of work it can perform.

Of course, the real reason it's cheap is because we're able to pass on all those pesky environmental costs onto those not born yet!
Yay for CHEAP (for us!) electricity!

You'll have a much greater power output with a motor that is driven directly by the chain(cog bolted to the flywheel) than you will with something being spun by friction with the rear tire. I've been super busy, but I promise I'll get you full details soon.

Yeah, but you'll also have much less efficiency. A well made bicycle dynamo will blow everything else out of the water in terms of efficiency.

For an extended duration, you can't generate more than about 100 watts and you probably can't generate more than about 50 watts without reducing your ability to cycle for transportation (which is an even more efficient use of energy that should not be compromised). So no matter how you slice it you're not going to make practical use of more than about 20-50W, which is best derived by the superior efficiency of a regular bicycle dynamo.


If you are lucky, you can generate about 100 Watts average while sitting on your trainer at home for a hour or so. But, let's say you can stick it out and pedal the trainer for 10 hours. If so, you will generate 100- Watt-hours, or 1 Kw-Hr. How much do you pay for a KW-Hr? I'll bet it's less than 25 cents, but let's assume you get a really bad deal and pay $1 for it. 10 hours of work to save $1 (or less) is pretty poor return on your investment. It also shows just how much of a bargain electricity is given the amount of work it can perform.

So, unless you live in the third world, or suffer from rolling blackouts, driving a generator off a bike is a waste of time.

Yeah, but that's only for electricity delivered to a fixed address. At present you can't buy mobile wireless electricity (http://en.wikipedia.org/wiki/Wireless_energy_transfer) no matter how much you're willing to pay; even though you can participate in almost every other aspect of society in a wireless mobile fashion.

That's why I feel it's more useful to try powering a regular bicycle dynamo while stationary. A fixed setup isn't worth it because it's too difficult to setup and dismantle when on the move and, as you note, electricity delivered to a fixed location is cheap (and as are sources like solar when compared to human-generated electricity).


Again, thanks guys. The library does sound like the best option...as I rarely actually need my laptop to create things. And anything I want to do on my site, I could probably just edit directly on the server.

But what if you're server is sitting in your panniers? I can't afford to tour indefinitely without earning a living and my server can't earn me a living without continuous access to a consumer IP address (which I can't buy from a commercial server company).