Most portable chargers won’t last long if you’re away from a power outlet for more than a couple of days. The vast majority of them need to be plugged in so their internal batteries can get recharged. Once they’re out of juice, you’re out of luck if you’re away from a socket.

The Brunton Hydrogen Reactor removes recharging from the equation by using hydrogen fuel-cell technology to generate power. It doesn’t require a power outlet to build up a charge, so it will come in handy for long camping trips, earthquake kits, and emergency go-bags.

If the Reactor looks familiar, then you probably know about the $100 Horizon Fuel-Cell MiniPak. The Brunton version is a licensed, reworked, and improved version of Horizon’s portable fuel-cell charger, rebranded for campers and hikers. Other than aesthetics, the main difference between the two products is that the Brunton charger's hydrogen cores have more capacity.

Photo: Tim Moynihan/WIRED

There are other portable fuel-cell chargers out there – some that use hydrogen as the main source of fuel and others that use different sources. There’s the hydrogen-based myFC PowerTrekk ($230), which can also be charged up using a power outlet. Toshiba’s Dynario charger (around $300) uses a squirtable liquid methanol solution to charge devices. The Lilliputian Nectar ($300) has a similar design as the Reactor, but it uses butane cartridges as its fuel source.

With a fuel-cell device, you’re basically developing electricity live and on-the-spot. The Walkman-sized Reactor uses removable and replenishable hydrogen cores, each of which are about the size of two C batteries stacked on top of one another. The rechargeable hydrogen cores are rated at 1,000 cycles apiece. When they're spent, you can recycle them as you would a soup can.

When a hydrogen core is loaded into the device, the Reactor’s internal fuel cell uses a platinum catalyst to separate positively-charged hydrogen ions from negatively-charged electrons. The electrons are routed through a circuit, supplying the electricity that powers your gadget. The hydrogen ions are shot through an electrolyte membrane, where they combine with oxygen from the air to create water vapor. You hear little puffs of vapor come out of the device as your gadget charges – water and mild heat are the Reactor’s only environmental emissions.

OLYMPUS DIGITAL CAMERA Photo: Tim Moynihan/WIRED

Compressed hydrogen gas and liquid hydrogen are both extremely volatile and dangerous, but Brunton claims the hydrogen stored in its rechargeable cores is much safer because it's stored as a more stable hydride. That said, the Reactor and its hydrogen cores have their own set of safety requirements: The Reactor is only approved for carry-on luggage in airplanes, no more than two hydrogen-core cells are allowed in your carry-on luggage, and you’ll need to keep the cells at temperatures below 120 degrees Fahrenheit.

The charger needs open air to operate correctly, so you can’t put it in an airtight bag while you’re charging your gadgets. And it won’t work on any camping trips to the Moon.

A USB-out port on the Reactor pumps out 5 volts at either 1 or 2 amps; you toggle between output levels by pressing the lone button on the side of the Reactor. The 1-amp setting is made for charging most pocketable devices, including phones, camera batteries, and GPS units, while the 2-amp setting is enough to charge an iPad. Brunton says each hydrogen-core cell boasts enough juice to charge your smartphone five or six times, but iPad-recharging caps out at about 1.5 times per fully-juiced cell.

The hydrogen-core cells recharge quickly (about an hour each), and their charging power doesn’t degrade quickly over time unlike a Lithium-ion battery. Once each cell runs out of juice, you’ll have to wait until you get home to recharge it; the separately sold hydrolyser refill device isn’t portable, and it requires a wall outlet to work. It also costs $250, but Brunton is working with retailers to offer free in-store recharging stations for the hydrogen cores.

Due in October, the $150 Brunton Hydrogen Reactor will come with two rechargeable hydrogen-core cells. Individual cartridges will go for $15 each, while four-packs will sell for $50. That’s not exactly a cost-effective scenario for everyday use, but it might be worth the investment for hardcore campers and hikers.