The Low-Down on Hydrogen E-Bikes

Imagine an e-bike powered by a battery the size—and weight—of a 16-oz. water bottle. For many e-bikes, that would mean a weight loss of 6-7 lbs. That’s what happens when an e-bike runs off of hydrogen rather than a lithium-ion battery. The German company HydroRide, using the brand name Hyrydis producing several different models of e-bikes, all of which are powered by hydrogen gas. They aren’t the first to consider using hydrogen for fuel in an e-bike.

The why of hydrogen gas is pretty interesting, Hindenburg notwithstanding. Here’s the first good reason to use hydrogen gas to power an electric motor: While an e-bike battery takes hours to charge, even with a 4 or 5A charger, a hydrogen tank can be filled or “charged” in mere seconds. The tank can be pressurized to 1 megapascal (MPa), which translates to 145 psi. Once charged, the tank can provide as much as 40 mi. of range on a single charge.

Here’s another reason why hydrogen is an interesting idea: Considering the size and weight of the tank, carrying additional tanks would be easy to do and purchasing additional tanks won’t come with a weight penalty of more than a few ounces. Doubling or tripling the e-bike’s range would not be difficult.

Yet another reason why hydrogen makes a compelling fuel: The exhaust is water.

Hydroride makes several different models of e-bikes. They offer a city model made for bike share programs, a folding e-bike and a “sport” e-bike that looks like it came from the set of a sci-fi movie thanks, in part, to a fork with only a left leg.

The key to the system is the hydrogen gas generator which is roughly the size and shape of a home oxygen concentrator used by people with respiratory issues. The hydrogen generator takes 200ml (6.7 oz.) and turns that into 5g of hydrogen gas over a 5-hour period of time. That 5g of hydrogen gas is what goes into the tank. Changing tanks on the e-bike takes about 10 seconds, they report.

The tank has a capacity of 390ml (13.1 oz.) and measures just 9.8 in. tall and 2.4 in. in diameter. One tank will hold 20g of hydrogen, which means that it takes about five hours to generate enough hydrogen to give an e-bike 40 mi. of range. That’s pretty close to what we see with many e-bikes.