Watching your phone or tablet steadily run out of juice when you're nowhere near a power outlet is stressful. Fortunately, there's no shortage of third-party backup batteries, and they come in every size, capacity, and price range to keep your device going when your battery icon starts to dip in the red. And it doesn't end there. Some power banks are equipped with features like fast charging, wireless charging, built-in cables, AC adapters, LED flashlights—even the ability to jump-start your car.
With so many options to choose from, how do you know which power bank is right for you? Read on for the most important points to consider.
Generally speaking, the bigger the battery, the higher the capacity and quantity of ports you get. Power banks that fit comfortably in your pocket are typically good for a full phone charge or two, while anything designed to keep you going all day is going to require a bag or a purse.
On the pocket-friendly front, most smaller batteries that maximize portability have a capacity of 5,000mAh and under, which gives you just enough charge to top up most phones once.
Once you get above 5,000mAh, battery size increases to the point where it's less likely to fit into your skinny jeans, but can still be stowed in a jacket pocket. There are even batteries that let you power laptops, and have enough juice to charge the average phone 10 times. Of course, they're some of the biggest and heaviest of the bunch, and definitely need to be carried in a bag.
The type of port (or ports) a battery has determines not only whether it is compatible with the devices you want to charge, but also charging speed. At a minimum, most battery packs will have a standard USB-A port for input and output. But with more phones, tablets, and laptops adopting the USB-C standard, you'll often find a USB-C port in addition to USB-A.
USB-C generally allows you to charge faster, consolidates input/output to one port, and can be found in many new phones. Now, you do have to be careful, because while some power banks have USB-C input, they don't have USB-C output.
Lightning is a proprietary Apple technology and it used to be hard to find power banks with a lightning cable or charging port. Thankfully, those days are over and there are dozens of excellent power banks made with iPhone users in mind.
Another factor to consider is how fast a power bank can charge your phone. Battery output is measured in voltage and amperage. Amperage (or current) is the amount of electricity flowing from the battery to the connected device, while voltage is the amount of potential energy. Multiplying volts by amps gives you wattage, the measure of total power. In order to make a device charge faster, most manufacturers either vary the voltage or boost the amperage in order to increase the total wattage. For most fast charging, you're looking at boosting or dynamically varying the voltage.
Essentially, for any kind of fast charging you need three things: A phone or other device with a charging circuit capable of using one of the fast charging standards, along with a battery and cable that support the same standard. If any one of these three things is missing, you won't be charging as fast as you can.
The two main fast charging standards you're likely to encounter are USB Power Delivery and Qualcomm's Quick Charge. Power Delivery is a newer protocol in which two compatible devices negotiate on the fastest charging option available, all the way up to 20V/5A (with an EMCA cable) if possible. It also allows for power to flow both ways.
Quick Charge, on the other hand, works by increasing voltage rather than amperage. These standard allows you to charge supported phones to 50 percent capacity in 30 minutes, which is especially helpful when you need power in a pinch.
Keep in mind, your phone will only take in as much power as its charging circuit is designed for, so even if you have it plugged into a 5V/2A battery, if it's only able to handle 5V/1A, that's the rate it will charge at.
For more, read our in-depth guide to fast charging.
There are a couple of other aspects to consider before selecting a backup battery. Pass-through charging lets you charge devices connected to the battery, while the battery itself is also being charged. If both your phone and backup battery are running on empty, this is a very useful feature.
Wireless charging has also become very popular, as it allows you to power up compatible devices without the need for a cable, but simply by resting them on top of the battery. Qi is the dominant standard that you'll find in compatible Apple and Samsung phones, and there are some battery packs out there that support it.
If you find that you often forget to carry your backup battery when you need it most, you might want to think about using a dedicated battery case instead. It combines the portability and protection of a case with a built-in power cell to keep your phone topped off at all times. The downside is that they often have lower charging capacities than dedicated batteries, and you really can't charge anything else with them.
Now, with all that in mind, we've rounded up some of our favorite power banks you can buy right now. You can't go wrong with any of them, so pick the one that fits your budget and needs.
Anker PowerCore 10000
Works With: Phones, Tablets
The Anker PowerCore 10000 ($35.99) is an affordable, compact backup battery that supports Qualcomm's Quick Charge 3.0 standard and can keep your phone running for an entire day of nonstop use thanks to a 10,000mAh battery. It isn't fancy, but it's powerful and economical, if you don't mind a lack of pass-through charging.
Anker PowerCore II 20000
Works With: Phones, Tablets
If one USB port isn't enough for you, the Anker PowerCore II 20000 ($59.99) offers double the ports and double the capacity (20,000mAh) of the PowerCore 1000.
Anker PowerCore+ 26800PD
Works With: Laptops, Phones, Tablets
Anker's all-out PowerCore+ 26800 PD ($129.99) adds a USB-C port to the list, letting you charge your notebook as well as your phone and tablet thanks to 26,800mAh of power. That's a huge boon for Macbook, Surface, and Chromebook users.
Aukey 8000mAh Sprint Wireless Charging Power Bank
Works With: Phones, Tablets
The Aukey 8000mAh Sprint Wireless Charging Bank ($29.99) is an inexpensive way to quickly charge your phone and tablet. This svelte power bank supports wireless charging via the Qi standard and has a USB-C port with Power Delivery (PD) 2.0, along with a USB-A port with PD 3.0. There's even a 5W USB-A port with adaptive charging for low-energy devices like Bluetooth headphones and wearables.
Aukey 10000mAh Power Bank With Power Delivery
Works With: Phones, Tablets
The Aukey 10000mAh Power Bank With Power Delivery ($29.99) features a 10,000mAh battery, a USB-C port with Power Delivery, a USB-A port with Quick Charge 3.0, and a traditional 5V USB-A port. For such a large-capacity battery, it takes just four hours to recharge via USB-C with an 18W charging adapter.
Belkin Pocket Power 5K Power Bank
Works With: Phones, Tablets
Belkin's Pocket Power 5K Power Bank ($29.99) is an inexpensive and durable portable charger. It features a 5,000mAh capacity battery that's small and light enough to fit in your bag or back pocket, with a single USB-A port with a 5V 2.4-amp output to quickly charge your phone. And the best part: Belkin offers a $2,500 connected equipment warranty should your phone be damaged while charging via the battery pack.
iMuto Portable Charger X6 Pro
Works With: Laptops, Phones, Tablets
The iMuto Portable Charger X6 Pro ($99.99) boasts a massive 30,000mAh capacity for a reasonable price, along with numerous ports and fast charging support. All that power makes it one of the heftier battery packs we've seen, at 1.5 pounds.
Mophie Charge Force Powerstation
Works With: Phones, Tablets
The Mophie Charge Force Powerstation ($99.95) can wirelessly charge your supported phones and tablets. It costs more than most 10,000mAh batteries, but that's because of the inclusion of the built-in Qi charging system. If your device is compatible, you don't need a cable at all.
Mophie Powerstation AC
Works With: Laptops, Phones, Tablets
Like its name implies, the Mophie Powerstation AC ($199.95) features an AC port for charging any device that needs a full-size power outlet, like a laptop. It's an expensive, chunky 22,000mAh battery, but it can be vital if a USB port just isn't going to cut it.
Mophie Powerstation Keychain
Works With: Phones
The Mophie Powerstation Keychain ($39.95) is one of the smallest portable chargers on this list. It also has one of the lowest-capacity batteries, at 1,200mAh. It has an integrated USB-C cable for charging your phone and another for charging the battery itself. And like most Mophie products it offers pass-through charging.
Moshi Porto Q 5K Portable Battery With Built-In Wireless Charger
Works With: Phones, Tablets
The Moshi Porto Q 5K Portable Battery With Built-In Wireless Charger ($84.95) is undoubtedly sleek, and has a gorgeous fabric surface for Qi wireless charging along with a rubberized ring and Moshi logo to hold your phone in place. Simply plug the 5,000mAh Porto Q 5K in and it works as a wireless pass-through charger for any smartphone. When you're on the go, you can also charge wirelessly using the internal battery or use the USB-A charging port.
Native Union Jump+ Wireless Powerbank
Works With: Phones, Tablets
In addition to sporting a 12,000mAh battery, the Native Union Jump+ ($99.99) supports wireless charging up to 5W with Qi compatible devices. It also has a Quick Charge 3.0 USB-A port, and a USB-C port that supports Power Delivery 3.0.
Nimble 10-Day Fast Portable Charger
Works With: Laptops, Phones, Tablets
Looking for enough battery capacity to charge both your phone and your USB-C-powered laptop? The 1.5-pound Nimble 10-Day Fast Portable Charger Bundle ($129.95) features a massive 26,800mAh battery in a relatively small footprint and can charge four devices simultaneously. It features three USB-A charging ports and a single USB-C port. The USB-C port provides 18W Power Delivery, and one of the USB-A ports features Quick Charge 3.0. Like all Nimble chargers, it's constructed from plant-based materials and features a magnetic cable management strap.
Nimble Premium Fast Charge Upgrade Kit 3-Day
Works With: Laptops, Phones, Tablets
Although the Nimble Premium Fast Charge Upgrade Kit 3-Day ($99.95) isn't the least expensive power bank on this list, it's one of the most versatile. At its heart, it's a 10,000mAh battery with a USB-C port with Power Delivery 3.0, as well as two 5W USB-A ports. The kit also includes a USB-C-to-Lightning cable for fast iPhone and iPad charging, a USB-C-to-USB-C cable, and a USB-C 18W PD wall charger.
RavPower USB-C Portable Charger 20100mAh Power Bank With QC 3.0
Works With: Laptops, Phones, Tablets
The RavPower USB-C Portable Charger 20100 Power Bank With QC 3.0 ($59.99) holds a massive 20,1000mAh battery in a relatively small case so it can easily recharge your phone several times and even give your laptop a decent power boost. It features a USB-A port with Quick Charge 3.0, a traditional 2.4V USB-A port, and a 3A USB-C port for laptops.
Samsung 25W Wireless Portable Battery
Works With: Phones, Tablets
While most power banks top out at 18W, the 10,000mAh Samsung Wireless Portable Battery ($79.99) has a maximum output of 25W for incredibly fast charging. The built-in wireless charging pad also gets a bump, supporting 7.5W output compared with 5W on many chargers.
Xiaomi Mi Power Bank Pro
Works With: Phones, Tablets
The affordable Xiaomi Mi Power Bank Pro ($29.99) is a stylish, pocketable 10,000mAh battery pack that can add more than a full day's worth of juice to your phone. It's a refreshing change from the usual clunky black bricks, with a sleek, slim metallic design.
The Best Wireless Chargers
Why fumble around for a charging cable when you can just sit your phone on a wireless charging pad? Whether you're an Android or iPhone user, we have the best wireless chargers to help you cut the cord.