Portable cell phone battery chargers have saved my bacon more than once while travelling. From overtaxing my iPhone taking holiday pictures to relying on Google Maps to get me where I’m going in a car without an aux port, there are times that low battery warning would trigger a major anxiety attack were I out and about without a power brick capable of refilling my phone’s tank at least once. But I’ve also made a habit of keeping one of them fully charged in a desk drawer at home, and you should too.
Chargers come in all sizes and capacities, from tiny cylinders that will recharge your smartphone once or twice to heavy bricks that will do so eight times or more. Because you’re going to be keeping this one at home rather than lugging it around in your purse, pocket or backpack, I say go big; who knows how long your power will be out, and you don’t want to be left without the power to keep in touch with emergency services, call friends and, perhaps most importantly, stream Netflix when your entire block has gone dark.
You have a wide range of options, prices and features to consider. Do you want something super basic that will get you through an unexpected brownout, or something that will serve if your power is out for a whole day? Wirecutter recommends looking for a USB-C charger rated for at least 15-watt charging; for micro-USB and USB-A, 8 watts or more should be the target.
These wattages will ensure your device will charge as quickly and efficiently as possible. In terms of capacity, you’ll want to calculate how many times you’ll be able to use a power bank to charge your device. An iPhone 11, for example, has a battery capacity of 3,110 mAh, so a charger with a 1,000 mAh capacity will give you three full charges. (You can figure out your device’s battery capacity with a quick Google.) The price will vary based on the brand, power capacity and weight. Since I’m recommending leaving this one at home, I’d say bigger is better.
If you truly want to be prepared for an emergency, consider getting a power bank capable of charging your laptop as well. These devices will have a regular AC outlet built in, which means you can actually use them to charge anything with a plug that runs on up to about 60 watts.