When you see how little energy a Tour d’France cyclist can generate, with their legs, over a given period of time, it becomes clear why these crank things are useless.
You could possibly charge a phone with a cycling setup, I haven’t done the math in a while. What I recall is the human body makes for a terrible generator.
Humans are efficient, and there are also huge losses in converting the energy from work to electricity, and then further converting this to whatever voltage you actually need, while also likely first charging a battery somewhere so you can use it at a different time than you are cranking/pedaling…
However humans are also strong and can think of mechanisms that help with leverage and whatnot; for example an elliptical machine would probably be better than a bike.
With that being said the power you can generate is still pretty small; around 100Wh is floating around. If you worked out more you’d make more, obviously, but that might not be feasible.
It’d still be more than enough for essentials like charging your phone though.
Fair enough. I’m not too worried about it charging (though I am confident that it will be an enormous amount of work and possibly take multiple passes while leaving the cell phone off). For me, this was more a “throw one more backup layer” on things; when I’m in the car and carrying what I normally lug around, I typically have:
The ~100Wh car battery and USB adapter off the cigarette lighter.
A tank of fuel to charge said battery.
A car jump starter (in case said battery goes dead), with its own battery that can do USB.
A laptop with its own battery with USB output.
A tablet with its own battery with USB output
A small power station.
A second, 100Wh power station.
A ~400Wh large power station.
An unfolding set of solar panels with another small power station.
The aforementioned solar/crank charger with a very small power station.
Having to actually crank anything is going to be about at the bottom of the list in terms of things that I’m going to be doing in any situation, so this is about 9 things that would have to fail subsequent to my cell phone battery dying in a situation where there’s an emergency for this to come up.
I did consider a more-serious charger at one point, but that would have been a pedal power station; it’s vastly easier to generate a given amount of electricity with your legs than your arms. If having it in the car or house is all you need, that’s probably a better choice if you’re worried about it (and you can definitely find video on YouTube of people charging phones with it):
There’s also someone that sells a tiny thermoelectric camping generator that can run on wood. If you’re really concerned about needing power, my guess is that it’s probably less-work to find something you can burn in that.
EDIT: I also have an AA-battery-to-USB-and-USB-to-AA-battery powerstation somewhere, but I don’t know if that’s actually in the car. I think that that’s at the house.
I would be legitimately interested in a demonstratably good crank charger, but it seems like there’s a million bad ones out there, that’s why I ask.
When you see how little energy a Tour d’France cyclist can generate, with their legs, over a given period of time, it becomes clear why these crank things are useless.
You could possibly charge a phone with a cycling setup, I haven’t done the math in a while. What I recall is the human body makes for a terrible generator.
Fair enough, good point.
Humans are efficient, and there are also huge losses in converting the energy from work to electricity, and then further converting this to whatever voltage you actually need, while also likely first charging a battery somewhere so you can use it at a different time than you are cranking/pedaling…
However humans are also strong and can think of mechanisms that help with leverage and whatnot; for example an elliptical machine would probably be better than a bike.
With that being said the power you can generate is still pretty small; around 100Wh is floating around. If you worked out more you’d make more, obviously, but that might not be feasible.
It’d still be more than enough for essentials like charging your phone though.
100w/hr, cycling constantly? How much food does that require?
It’s just not realistic. As I mentioned, I’d read some math breaking down what a Tour d’France cyclist could do for a battery, and it was paltry.
Better off investing in solar at a rate of 5-10x your battery capacity. Then you can charge reasonably fast in most conditions.
Fair enough. I’m not too worried about it charging (though I am confident that it will be an enormous amount of work and possibly take multiple passes while leaving the cell phone off). For me, this was more a “throw one more backup layer” on things; when I’m in the car and carrying what I normally lug around, I typically have:
The ~100Wh car battery and USB adapter off the cigarette lighter.
A tank of fuel to charge said battery.
A car jump starter (in case said battery goes dead), with its own battery that can do USB.
A laptop with its own battery with USB output.
A tablet with its own battery with USB output
A small power station.
A second, 100Wh power station.
A ~400Wh large power station.
An unfolding set of solar panels with another small power station.
The aforementioned solar/crank charger with a very small power station.
Having to actually crank anything is going to be about at the bottom of the list in terms of things that I’m going to be doing in any situation, so this is about 9 things that would have to fail subsequent to my cell phone battery dying in a situation where there’s an emergency for this to come up.
I did consider a more-serious charger at one point, but that would have been a pedal power station; it’s vastly easier to generate a given amount of electricity with your legs than your arms. If having it in the car or house is all you need, that’s probably a better choice if you’re worried about it (and you can definitely find video on YouTube of people charging phones with it):
https://www.k-tor.com/shop/generators/power-box/
There’s also someone that sells a tiny thermoelectric camping generator that can run on wood. If you’re really concerned about needing power, my guess is that it’s probably less-work to find something you can burn in that.
googles for the name
“BioLite”
https://www.amazon.com/BioLite-Campstove-Electricity-Generating-Charging/dp/B00FU8RBPE/
EDIT: I also have an AA-battery-to-USB-and-USB-to-AA-battery powerstation somewhere, but I don’t know if that’s actually in the car. I think that that’s at the house.