Solar electric bike?

[thegrapsman]

Has anyone ever tried to strap a decently powered folding solar panel on the back of an electric bike? I'm just curious if it would actually work to power it, maybe even if you have to charge on the grid first but the solar helps keep the charge? If anyone has done this or has some links about it, lmk.

 

[autumn]

Has anyone ever tried to strap a decently powered folding solar panel on the back of an electric bike? I'm just curious if it would actually work to power it, maybe even if you have to charge on the grid first but the solar helps keep the charge? If anyone has done this or has some links about it, lmk.

Your minimum electric bike setup will be a single 400w motor. A folding solar panel isn't going to cut it unless you leave the bike sitting untouched for days in direct sunlight in between using it for only an hour or so.

 

[Matt Derrick]

yes, unfortunately, the battery on an electric bike is pretty big, and solar panels of the kind you're talking about are very very slow to charge a battery that big. like honestly, we're talking about weeks and weeks here, not days. it would be far more efficient to stop and recharge the bike for 8 hours on an outlet than it would be to recharge with solar.

an alternative would be to pick up a small gas motor made for bicycles. a good one runs about 800 bucks, but the gas mileage is like 70 miles per half gallon or something ridiculous like that. @Hillbilly Castro has one of these motors and could probably tell you a lot more about them than i could.

 

[meatcomputer]

if you wanted to piss off absolutely everyone. You could get a gas generator to charge your electric bike. Or a coal powered generator.

 

[autumn]

yes, unfortunately, the battery on an electric bike is pretty big, and solar panels of the kind you're talking about are very very slow to charge a battery that big. like honestly, we're talking about weeks and weeks here, not days. it would be far more efficient to stop and recharge the bike for 8 hours on an outlet than it would be to recharge with solar.

an alternative would be to pick up a small gas motor made for bicycles. a good one runs about 800 bucks, but the gas mileage is like 70 miles per half gallon or something ridiculous like that. @Hillbilly Castro has one of these motors and could probably tell you a lot more about them than i could.

Yeah, that's the way to go. You can just use a weed whacker motor though. A gas engine kit for a bicycle is faaar more expensive than it's constituent parts. A weed whacker or lawnmower engine, couple of sprockets, an extra chain, extra brake lever for the clutch, throttle grip, 8:1 gearbox or similar (if using a weed whacker engine, since those idle @ like 2krpm and redline at 12+krpm) and that's about all you need. Takes a couple of days to put together. The only part that's difficult is fabricating a mount for the motor. It can be done without a welder, but having a welder makes it way easier. $10 in metal or so, a little creativity and a couple of hours is all you need. If you gear it properly you'll get 80-120mpg depending.

 

[thegrapsman]

Thanks for the input everyone!
I looked up the wattage etc and maybe if I built a camper to tow with the bike I could mount a high powered solar panel onto it but the shit would be expensive as fuck. I also seen gas motor set up kits on walmarts site that are pretty cheap, problem is even though I'm handy idk shit about setting up stuff involving motors so I'd be a little afraid of totally fucking it up.

 

[thegrapsman]

Also where do you charge electric bikes anyway? Just in case I actually do get one..

 

[laughingman]

I know this is a rather old post. This is a thing that people have sort of figured out how to do now. There is a large race of solar powered ebikes that rides across Europe and Asia every few years. They are supposed to be coming to the states soon. These are big custom built rigs. But it gives you an idea of how much power you need.

https://www.thesuntrip.com/en/2022-sun-trip-america-california/

 

[The Toecutter]

Has anyone ever tried to strap a decently powered folding solar panel on the back of an electric bike? I'm just curious if it would actually work to power it, maybe even if you have to charge on the grid first but the solar helps keep the charge? If anyone has done this or has some links about it, lmk.

Depends upon a lot of factors. How big is the solar panel in its dimensions and what is its wattage output in direct sunlight? It is quite likely that the solar panel could add more watts of drag at your cruising speed than the amount of power it could generate at said speed, actually costing you range.

I'm about to add solar panels to my etrike build, but my "bicycle" is more than a bit of an oddity, as I designed the bike to have a streamlined body(30 mph can be maintained on flat ground with 400W power draw from the battery and no pedaling, although my next body will have about 1/3 the aerodynamic drag), and the solar panels I'm about to install are flexible and will conform to the curvature of the body shell, thus avoiding the imposition of additional aerodynamic drag. I have five 50W panels, and they will all be set up in parallel. However, that does not mean I will get 250W in direct sunlight, as each of them are on different points of the body. I expect in direct sunlight somewhere around 100-150W in ideal condition, which would mean somewhere around 500 Wh of energy per day generated. This would theoretically be enough for me to travel 50-70 miles a day on solar power at 30-35 mph using the motor plus light pedaling effort. On a normal ebike, you'd be lucky to get 15-20 miles of solar a day in the same conditions.

 

[ohmegatron]

Has anyone ever tried to strap a decently powered folding solar panel on the back of an electric bike? I'm just curious if it would actually work to power it, maybe even if you have to charge on the grid first but the solar helps keep the charge? If anyone has done this or has some links about it, lmk.

I'm looking into something similar. I'm building my first ebike from a conversion kit to hopefully cycle across Canada. Large parts of this country are sparsely populated, and I'm not certain I'll be able to charge my batteries every day or night, so having a solar inlet will be useful.