When a smartphone or tablet battery just can't cut it on a long trip, we turn to USB battery packs that deliver lifesaving, phone-charging reserves. They're typically lithium-ion based, like smartphones, but are larger and devote every millimeter of available space to a hefty battery. Over the past couple years, another category of rechargers have started to pop up, giving outdoorsy types an alternative to lithium-ion batteries with something that feels vaguely futuristic: the hydrogen fuel cell.
Fuel cell cars are still a novel concept, and automakers haven't pushed them to market yet to compete with electric and hybrid vehicles. But on a small, handheld scale, hydrogen fuel cells can hold their own. Compared to lithium-ion battery chargers, they're not cheap. And they're not exactly good for the environment in the long run, either, even though they produce harmless water vapor when producing electricity.
So what are the advantages of fuel cell chargers? Let's start with an example: the new Brunton Hydrogen Reactor, which costs $150. For that price, the Brunton comes with two hydrogen-core cartridges, each of which provides around 9000 mAh of electricity--enough to charge the average smartphone about six times. This video does a good job of explaining how the device works.
The key difference between fuel cells and lithium-ion chargers is the swappable cartridge. Typical battery chargers have to draw power from a wall outlet or another powered device, like a laptop. With a charger like the Brunton, each individual cartridge offers another six phone charges of juice. Of course, those cartridges need to be recharged, too, and that's not so easy.
Any battery-based charger can plug into a wall socket, but fuel cells need special rechargers. With the Bruton, you can either buy a $250 hydrolyser charging station that uses water to recharge the cells, or take the cartridges to commercial recharging stations that Bruton plans to set up in stores.
Fuel cells aren't cheap. Comparitively, Wirecutter's recommended Satechi Portable Energy Station 10 provides 10,000 mAh of juice--roughly the same as a single hydrogen cartridge--and costs $60. You don't need any special gear to recharge it.
Unlike lithium-ion batteries, though, the fuel cells won't gradually diminish in capacity.
Unlike lithium-ion batteries, though, the fuel cells won't gradually diminish in capacity. They're good for 1000 cycles and can be recycled. Unfortunately, they're not as environmentally friendly as they seem, since most hydrogen is refined using traditional fossil fuels.
Hydrogen isn't the only source of energy companies are leveraging for fuel cells. The Lilliputian Nectar uses butane cells to provide a claimed two weeks of battery life, or more than 10 full charges of the average smartphone. But the device costs $300, and non-rechargeable cartridges cost $10 apiece.
Though the technology behind fuel cells is exciting, lithium-ion batteries are still far more practical (and affordable) for the present.