Smartphones can be important tools in an emergency. Besides providing the chance to call for help and other emergency features you phone may offer, a phone can act as a flashlight, compass and GPS. But all of a phone’s functions rely on the battery and the features most useful in a pinch are the ones that consume the most charge.

Once the battery is flat, the phone becomes nothing more than a lump of plastic and metal. There are, however, a few ways to charge your phone in an emergency, when a power outlet or computer isn’t available. These solutions range from mundane to truly innovative.

Car Charger

how to charge your phone in an emergency

Let’s start simple.

Car chargers are cheap, widely available for all sorts of devices and vehicles, and will work so long as there’s a vehicle nearby with an energy provider.

Most car chargers work in the same way, so buying a specific version isn’t important. Just remember that iPhones will need a compatible charger or an adapter. Also keep an eye out for dual-USB chargers, which are handy if you’d like to charge two phones or a phone and a second device.

Backup Battery

emergency phone charger

In many situations a car charger is all you’ll need. But what if a car isn’t available, is out of fuel/battery, or you don’t want to waste gas on charging a phone? That’s where a backup battery comes in.

These products are literally large batteries with ports for connecting phones or other USB device. Those designed to charge smartphones are usually no larger than one, so they’re easy to store in a drawer, backpack or glovebox. And while not cheap, batteries large enough to fully charge two phones can be purchased for under $50.

A backup battery is a temporary solution, however. Eventually it too will run out of charge, so you’ll be left back at square one. Batteries also lose charge over time (even when not in use) and can be damaged by extreme temperatures.

Solar Charger

emergency phone charger

Unlike the first two options, a solar charger fully solves the problem. You can theoretically use a phone indefinitely without access to central power if you have a solar charger. All that’s required is access to the sun, and even a moderately overcast day will produce enough energy to charge your phone.

Size can be an issue, however. While pocket-size chargers are sold, they don’t work well. A larger folding charger is needed for reliable power. Cost can be an issue, too, because large panels sell for between $100 and $200 online. Still, no other option can match the versatility and reliability of solar.

Hand-Crank Charger

emergency phone charger

You’ve probably heard of hand-crank flashlights, but did you know there are hand-crank chargers? Yep, it’s a thing, and you can buy one for $60 online. Hand-crank chargers work by converting the energy of your crank into charge, which is then transferred either to your phone or an internal battery. This means they always work. If you can crank, your phone can charge.

Don’t expect it to charge quickly, however, unless there’s also charge stored in the internal battery. Most modern smartphones will require a few minutes of cranking before they have enough charge to send a text, and any real conversation demands a good ten to twenty minutes twirling away. These problems make hand-crank chargers an option of last resort.

BioLite CampStove

how to charge your phone in an emergency

Here’s an idea. Instead of charging your phone with something built for only that purpose, why not charge while performing another essential task? Like, say – cooking!

That’s what the BioLite CampStove offers. Unlike most camp stoves, which run of small canisters of fuel (like propane), the BioLite stove is engineered to run off almost any flammable biomass. Twigs, leaves, pine cones – this stove can burn it all. Once the fire starts its energy can be harnessed to charge USB devices. Or make dinner.

The BioLite sells or $129.95, which is a bit expensive. And while small for a camp stove, this is by far the largest device on this list. But if you can find storage, or you’re planning to camp anyway, this stove is a great way to keep your phone charged.

Conclusion

These five options cover many situations. There’s no single choice that is best in ever scenario, but all are reliable. If you can only have just one besides the car charger (really, everyone should have a car charger, even if you don’t own a car), I recommend picking a hand-crank charger with internal battery.

Want to know more about how to charge your phone in an emergency? Read our guides on extending battery life and using a smartphone in extreme weather And if you're in the market for a new phone, don't forget to check out our smartphone review and buying guide.