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Comment by tgb | Hacker News Reader

Maybe I'm missing something obvious, but how does an electric bike that can be locked anywhere get charged? Do they have people going around replacing the batteries when they get low? How long does a battery last anyway?

Edit: solar panel judging off pictures of the Jump bikes?

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It's an assist electric bike. It's not like riding a moped or a motorcycle. You still have to pedal, but the bike kicks in the electric motor during some situations (such as when going uphill or starting from a dead stop) to make the pedaling easier. When the motor isn't on (such as when you're going downhill or slowing down), the battery recharges itself using your pedaling.

edit: as pointed out, this type of charging only extends the battery a little bit. It turns out that JUMP (the company behind these bikes) actually sends out crews to pick up bikes with low battery and takes them back to their office to recharge [1].

1: https://sf.streetsblog.org/2018/01/11/san-francisco-issues-p...

Recuperation alone would prolong the max. distance by max 5% or so. If you would have to recharge the battery while pedaling this wouldn't be a great experience. Together with the heavy weight of a ebike this wouldn't make any sense.

Maybe it charges under braking only.

Recuperation for ebikes is more a marketing thing than something which will extend your ride.

You're right, I found this article [1] which actually mentions that the bike company sends out crews to pick up bikes with low battery and takes them back to their office to be recharged.

1: https://sf.streetsblog.org/2018/01/11/san-francisco-issues-p...

It appears that through their Social Bicycling program, JUMP bikes offer a $1 credit to people who lock a bike to a charging hub, rather than just a ‘dumb’ bike rack or pole. JUMP claims that bicycles typically require a charge every 48 hours. I’d assume it’ll work the same way with Uber Bike.

Keeping the conservation of energy in mind, any other method of charging isn’t feasible.

This is a fantastic solution to the issue, and could help solve the issue of bikes getting dumped everywhere. Combining the dock and dockless models!

Yup. Solar. The JUMP app actually shows each bike's location and how much power it has.

Yesterday I picked one up that was in the shade all day and lost power 10 blocks from my house. It was a huge difference. Those bikes are heavy so they're harder to pedal without power.

Because it's assist - I wonder if it charges while braking

I doubt that would be enough to charge it. Braking is generally done infrequently.

It can charge while you’re pedaling :)

Practically no electric cycle charges via recuperation. This would only be possible on bikes that have the motor attached to the wheel (either front or back) and not for bikes that have the motor at the pedal (you’d need to have the chain fixed and transmitting power when rolling) You could also only brake with one wheel and bikes have the better brake on the front wheel due to weight distribution but powered front wheels are uncommon. You’d also need a set of sensors on the brakes, all the electronics for charging etc.

It’s usually just not worth it unless you live in a mountainous region. Bionix from Switzerland offers recuperation but it’s the only one I know.

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