Gene'sG

The force required to pull is directly related to the watts required to power or charge what you have connected. A smaller motor won’t make much difference. The TV you see in the video only needed about 35 watts and was easy to pull. Plugging in a laptop (65 watts), iPhone (12 watts), iPad (12 watts) and a battery pack (13 watts) makes for a good workout.

It really depends on the load. If I plug in around 100 watts of resistance, for example my laptop (65 watts), iPad (12 watts), iPhone (12 watts) and a battery pack (13 watts) its comfortable and consistent with what a typical rowing machine feels like. Less than that and it’s too easy, more than that just makes it a more challenging workout 🙂

The capacitors are needed as a buffer to keep a steady flow of power during the return stroke on the rower when less power is being generated.

I totally agree!! Much of the reason I’ve built these human powered generators, I felt like I’m wasting perfectly good energy as heat that could actually power something.

I was just thinking about adding a second string of capacitors this weekend! The fact is, the ones I used are pretty close to the right capacity. Doubling them should be more than adequate for my capability. I’ll need a bigger project box, it’s pretty crowded already.

Agree, if you’ve got kids around that flywheel could be a hazard. A shroud would be a nice add on.

Thank you!

That one might work - if you go that route, take out the magnetic resistance parts and measure the shaft before ordering the shaft coupler. It also looks a little narrower and might pose some issues fitting the coupler.This one looks like an exact match to the trainer I used:https://amzn.to/3i4EasS

Hi Sheridan233 - this one will work: https://amzn.to/2KSvFoN

Hi Moderate,That really depends on how you want to charge it! I use a pedal generator and am really happy with the way this 15A adjustable charge controller works: https://amzn.to/3nTwTOkIf you plan to charge using solar, then I'd suggest a good MPPT charge controller like this Renogy: https://amzn.to/346hgM2 paired with a decent solar panel like this Renogy 100w https://amzn.to/37V5O6Nor if you want something built to travel this RockPals 100w comes with Anderson connections so would be easy to hook right up: https://amzn.to/3ndtlGOIf you just want to charge it with AC, I'd probably go with this one, but change the alligator clips to Anderson PowerPoles: https://amzn.to/3oEqrerGlad to answer any other questions you have.

Exactly right, Ben - everybody has their own goals for these projects. I went for the LiFePO4 batteries for lighter weight and faster charging capability. I like your custom wood panel inside your ammo can, much fancier than my cardboard!

Hi Rep828 - I added a video on the last step to show how I charge and use the portable power station. I have a charge controller on my pedal generator.

The quality of the circuit in the USB ports that came with the kit are likely not as efficient as the better quality USB socket adapters, but I haven't done a test to prove that. I was basing that on how hot they get after just a little bit of use.

6 lb, 3.6 oz

Thanks for that, makes sense!

I have just what you’re looking for - take a look at my bike trainer pedal generator design - http://genesgreenmachine.com/best-design-diy-bike-trainer-pedal-generator/With that design, you can leave the tire on the bike, generate when you need to, pop it off the trainer and ride whenever you want to!

Good question! I'm sure you could leave the resistance unit in place, but would need to find a way to connect the generator motor. That could get complicated, you'd probably need a custom adapter. As long as there is enough distance between the motor and the resistance unit, there shouldn't be much interference. If you're looking for a setup that allows you to generate electricity, and still be able to add resistance, check out my other 'able using a spin bike: https://www.instructables.com/Spin-Bike-RC-Motor-Pedal-Generator/ That design allows for both, and benefits from a much bigger flywheel!

Thank you, and nice work! I considered using an old drill for this project too, but you are right - really noisy. Using the RC motor is much quieter for 2 reasons: (1) there are no gears (2) there are no brushes. If you watch the videos, you can easily hear me talking while I'm demonstrating the generator - it is fairly quiet to operate.As far as voltage regulators go, it's a good option if you are charging/powering devices that are sensitive to higher voltage, or you want to put a specific voltage into a device/battery, or you just don't want to watch the meter. I like this regulator, however if you need up increase (step up) the voltage like in your case, this one should do the trick.

Hi uWave - what you are proposing makes a lot of sense. When I initially set out on this journey of building pedal generators, my intent was to make a product or products I could sell. Those dreams were squashed by the accounting department (wife) and the scheduling department (also wife) so with limited time and funds I decided to just give away my designs - and here we are. I make a few dollars a month by people following my links to Amazon, so I guess that's something for my time. In my first design https://www.genesgreenmachine.com/build-spin-bike-pedal-generator/, I did add a charge controller which works perfectly for powering anything 12v (up you the limit of you and/or the charge controller). Creating a purpose build PCB with a controller that gives both 12v and USB 5v output,…

Hi uWave - what you are proposing makes a lot of sense. When I initially set out on this journey of building pedal generators, my intent was to make a product or products I could sell. Those dreams were squashed by the accounting department (wife) and the scheduling department (also wife) so with limited time and funds I decided to just give away my designs - and here we are. I make a few dollars a month by people following my links to Amazon, so I guess that's something for my time. In my first design https://www.genesgreenmachine.com/build-spin-bike-pedal-generator/, I did add a charge controller which works perfectly for powering anything 12v (up you the limit of you and/or the charge controller). Creating a purpose build PCB with a controller that gives both 12v and USB 5v output, along with a meter in a nice box that can be mounted on handlebars was actually part of my "grand plan" design. Meter should show amps, watts, volts, total watt hours and total time (along with a reset button). Also adding in bluetooth LE output for watts generated for the Zwift users out there was another feature that I'd include. You'd probably sell the heck out of that. Happy to collaborate with you on the design if you'd like my guidance.

So thrilled to hear you built it - please share a picture of your build! The challenge when you get up in watts drawn is we humans aren't creating steady power - it's very difficult to keep the pedals cranking at exactly the same speed/power. You've also hit on the solution by adding the super capacitor. The other option is to drop in a 12v lead acid battery to the circuit, which is the approach I have personally taken. Adding the battery works as a buffer of our varying input (likewise with the ultra-capacitor), smoothing out the voltage input to the inverter.

Hi alcurb - if you're looking for an easy build "bike generator->TV", I've put together an -ible you might want to check out:https://www.instructables.com/Best-DIY-Bike-Trainer-Generator/

As cool as it might, be - I’m never going to be able to produce 2400 watts with these legs (show me a human that can). By the way, the motor I use has more capability than I’ll ever push - it’s max rating is 1820 watts, so the limiting factor on watts produced will be the person spinning the cranks on the bike. I’ve personally generated almost 400 watts with this setup (and I’m an old, out of shape, fair weather mountain biker), I’m sure others can do much better.

Very cool - sounds like it would work much better than your standard fair duct tape, I might have to get some! Looks like you can find it on Amazon too: https://amzn.to/2Gu9JM0

I’ve used MakeXYZ before with good luck. https://www.makexyz.com/

Thanks rrwood! Don't believe for a second I haven't thought about coming up with some kind of Zwift integration. Just haven't figured out all the details yet...

Hi Garzo - I agree with the idea of a smart charger, I use the same for charging a Lipo battery. However, I've avoided using a step down regulator by designing this to produce power within the voltage range that is suitable for using car chargers and inverters. The regulator would add another area of power loss, and efficiency was one of my goals. You certainly could add a regulator if you really need fine control of voltage, but isn't necessary for charging/powering as I demonstrate.

Hi Simon, to help answer this question, I created another video and added it under the "Charge!" section. If your question isn't answered after watching that video, I'll be happy to clarify.

Thanks, WeavingBird! As much as I sweat, I really need the fan :)

If you do, please share a picture of your build - I'd love to see it!

Good question! There are a couple reasons:1. DC motors typically use brushes, which are both noisy, and can wear out2. AC RC motors come is a wide range of Kv ratings, so I was easily able to find one that matched the RPM of the trainer drive shaft to get us to the ideal 10-15 charging volts.

Thanks so much, Matt! Really appreciate the positive feedback.

I've got to try these - peanut butter cups are my kryptonite! Thanks for sharing, well done!

Very good point, Lorddrake! One of the very reasons I like this Drok meter as you can set it up to blink the screen when you reach an upper limit on voltage. I used this meter for the box you see in the video mounted on the bike. Another nice feature of this meter is it 'remembers' the total watt hours generated even if you stop pedaling.

Good tip! Thanks Lorddrake.

I see your quandary - let me try to clarify. To your last statement - the current (amps) will be defined by the load, so when I’m charging my 5500mAh 11.1v Lipo battery, the proper settings to charge it are 5.5 Amps and the volts are managed by the balance charger, starting out at whatever the battery is at, usually around 11.2v. Watts = volts * amps, so we get 61.6 watts of resistance while pedaling. Not exactly - the charger isn’t 100% efficient, so that load is more like 70 watts. The wattage will actually increase as the battery charges until the battery gets to 12.6v, at which time it will taper off as each cell reaches a fully charged state (which makes for a good cool down). To your question about which motor to choose, what you really need to determine is what RPM…

I see your quandary - let me try to clarify. To your last statement - the current (amps) will be defined by the load, so when I’m charging my 5500mAh 11.1v Lipo battery, the proper settings to charge it are 5.5 Amps and the volts are managed by the balance charger, starting out at whatever the battery is at, usually around 11.2v. Watts = volts * amps, so we get 61.6 watts of resistance while pedaling. Not exactly - the charger isn’t 100% efficient, so that load is more like 70 watts. The wattage will actually increase as the battery charges until the battery gets to 12.6v, at which time it will taper off as each cell reaches a fully charged state (which makes for a good cool down). To your question about which motor to choose, what you really need to determine is what RPM range you will be in, from low to high. If you’re using a bike with multiple gears, you can always adjust the RPM by shifting up or down. The load will remain relatively constant, and as long as you are in the voltage range of the charger (10v-28v), the charger will be happy. I think your calculations to go with a 63kv motor are off a bit as this would put your voltage at about 68 volts @ 15MPH (using a mountain bike tire as I have in my calculations). Don’t overthink the motor, I’d go with a 320kv for a mountain bike tire and a 350kv for a road bike tire.

Yes, you certainly could, depending on your fitness level. That balance charger should work perfectly, with the added benefit that it accepts a pretty wide range of input voltage. The great thing with these balance chargers is you can always adjust the amperage down if you physically can’t maintain the max wattage needed to charge a battery.

Thank you! Glad you like it. No reason why you couldn't use this to charge an RC LiPo battery, although I haven't tried it. The input voltage for a typical B6 IMax or similar Lipo battery charger is 11-18v, right in the sweet spot of this design. The nice thing with using a Lipo battery is you can put a lot of watts (50, max) into the battery in a short time. Typical USB battery packs will only accept 5 watts charging, and quick charge 3.0 battery packs top out at 18 watts. I like your idea! I'll have to get a Lipo battery and one of these chargers ( http://amzn.to/2jzAoKf ) and try it out! As long as the volts out of the Lipo are between 9 and 24, then any good USB car charger will charge your devices with the battery. Great thought!