Anyone who travels knows the importance of carrying a backup battery. But due to the vast number of options available, you’re likely to feel overwhelmed when shopping for one. Besides the various charging specs, ports, and even cables you have to consider, there are a ton of competing brands. How are you supposed to know which ones offer the best value?  

Well, we’ve done the work for you, testing a wide range of power banks from different manufacturers, across different price points. We put each power bank through the ringer, too, subjecting them to a battery—pun intended—of tests. You can read more about our testing process in detail below. While our picks reflect a range of needs, you might also consider our roundup of USB car chargers if you spend a lot of time in transit; or check out our roundup of best power stations if you’re in the market for a more substantial power source—one that can power your appliances in an emergency or while off-grid.

Mophie Powerstation XXL – Best overall

Pros

• Incredibly efficient
• Sleek fabric design
• Small footprint

Cons

• The indicator lights are an afterthought

Building on the success of the Powerstation Plus XL (our previous pick for best overall power bank), Mophie’s Powerstation XXL matches its predecessor in efficiency, achieving 92.51 percent of its stated maximum current, plus it’s stylish, portable, and affordably priced. It’s a no-brainer recommendation if you’re in the market for a dependable power source on-the-go.

Read our full
Mophie Powerstation XXL review

Tronsmart Presto PBT10 – Most portable

Pros

• Small and lightweight
• Efficient
• QC 3.0 compatible

Cons

• Port alignment inside isn’t exact, but it still works

Small enough to fit into a coat pocket or the side pocket on a backpack, the Tronsmart Presto is an obvious companion when you’re on-the-go. It’s a 10,000mAh (37Wh) pack, with two USB-A ports, one with QC3.0 for fast charging.

Read our full
Tronsmart Presto PBT10 review

Otterbox Fast Charge 20,000mAh – Best USB-C power bank with Power Delivery 

Pros

• Well designed
• Reasonably priced
• Supports multiple charging standards

Cons

• Would love to see another port or two on it

With above-average efficiency, a rugged case, and Power Delivery, Otterbox’s Fast Charge power bank is a great option for your bag. It could easily be our pick for best overall power bank, if not for the fact that our top pick—Mophie’s Powerstation XXL features more ports.

Read our full
Otterbox Fast Charge 20,000mAh review

Einova Laptop Power Bank – Most stylish

Pros

• The display is actually useful
• Fabric covering is a nice touch
• Above-average efficiency

Cons

• Both USB ports should have the same charging speeds

With its stylish fabric-clad body, its discreet yet useful battery-status display, and its three USB ports (one of which is USB-C), Einova’s power bank adds flair and above-average battery efficiency to your everyday carry.

Read our full
Einova 64W Ultra-Fast Power Bank review

Powercore Fusion 5000 2-in-1 Portable Charger and Wall Charger – Best budget option

Pros

• Built-in wall adapter
• Two USB ports

Cons

• Not the most efficient battery pack we’ve tested

The combination wall charger and portable power bank format makes the Powercore Fusion 5000 exceedingly convenient. The bank itself can be recharged via either method—power outlet or MicroUSB port. It’s limited to two USB-A ports for device charging, but that doesn’t dimish its great handiness-to-cost ratio.

Read our full
Powercore Fusion 5000 2-in-1 Portable Charger and Wall Charger review

Sherpa 100AC Portable Power Bank – Best for road warriors

Pros

• Informative display
• Airline approved
• Numerous ports

Cons

• Pricey
• Slow wireless charging

If you spend a lot of time on the road and value device preparedness, the Sherpa 100AC makes a trusty, if pricey, companion. Yes, at $299.95, you’re looking at a big investment. But that buys you two USB-C ports capable of fast-charging speeds, two standard USB ports, a Qi wireless charging pad, a standard U.S. 110V outlet, a full complement of cables, and a nifty status display and buttons for controlling various functions of the pack. The pack itself can be charged in just a couple hours.

Read our full
Sherpa 100AC Portable Power Bank review

Belkin 10K USB-C Power Bank with Integrated Cables – Most novel convenience

Pros

• Built-in cables
• 18W output
• USB-C and Lightning supported

Cons

• Average efficiency
• A little pricey

Belkin’s Charge Plus 10K USB-C Power Bank is a capable mobile companion in its own right—both its USB-C and Thunderbolt ports are capable of delivering 18W of battery power to your device, or 23W total if both ports are used simultaneously. But it’s the built-in cables for each port that really sets this power bank apart. Of course, you’ll pay a slight premium for the convenience.

Read our full
Belkin 10K USB-C Power Bank with Integrated Cables review

RAVPower Portable Power Station 252.7Wh Power House – Best power station

Pros

• Small form factor
• Plenty of ports
• Comes with a case and built-in flashlight

Cons

• Built for quick trips, not for extended use

There are times when a mere power bank isn’t enough—the circumstances call for a power station. Say you’re spending the weekend off the grid. Or you want to be prepared for a future emergency. The RAVPower Portable Power Station 252.7Wh Power House will get the job done. With a capacity near 252.7Wh, a nice complement of ports, a built-in flashlight, and an included carrying case, this highly portable power station makes a great travel companion for road trips. (For more options, see our roundup of best portable power stations.)

Read our full
RAVPower Portable Power Station 252.7Wh Power House review

How we test

Determining whether a power bank lives up to a company’s promise entails more than simply connecting it to a phone and charging. Testing battery packs is done over weeks, not days, and requires extra equipment in order to ensure the batteries work as expected.

1. Upon receiving each battery pack, it’s fully charged, using indicator lights as a means to track charge level.

2. Then to track efficiency, we use an AVHzY USB Power Meter in tandem with a DROK Micro Load Tester.

As we use the DROK load tester to drain the pack of power, we are able to test against a battery’s stated maximum current, and verify that proper shutdown mechanisms are in place should something go wrong during a charging session (such as a device drawing over the maximum amps).

By using the AVHzY USB Power Meter, we are able to monitor volts and amps, total power throughput, and total amount of time to deplete a battery from full to empty. The meter can create an Excel spreadsheet of the entire process for future reference.

3. Next, we recharged the battery, this time using the AVHzY to track it and chart the amount of time it takes to reach full charge.

The AVHzY meter solves a shortcoming we had with our previous method with the PortaPow. Previously we had to use a GoPro camera to track each battery through its charge cycle, as the PortaPow monitor would continue to collect data after the battery was fully charged (trickle charging is normal, and unfortunately interferes with our testing).

If a battery was capable of charging through USB-C, we use that instead of Micro-USB.

4. The AVHzY also has a feature built in that checks a charging port for all of its supported charging standards. We are able to run that test and get an instant readout to confirm support for QC 3.0, for example, without needing to have compatible phones or devices on hand.

Power source and cables
All of our tests were conducted using the same wall adapter and, when possible, USB-C or Micro-USB cable. This was done to eliminate any discrepancies with wall adapters and cable throughput.

What to look for in a portable power bank

Without fancy testing equipment, you never truly know if you’re getting what you paid for with a battery pack. Vendors, especially in Amazon listings, like to throw around a lot of terms and certifications.

Here are a few tips to help you make a decision:

• For those with a compatible device, make sure the battery pack is Quick Charge 2.0, 3.0, or PD certified. Depending on your smartphone, this can make a big difference in performance. If you own a QC 2.0 device, however, ask yourself if paying extra for a QC 3.0 capable pack is worth it.
• Don’t put 100 percent confidence in a company’s claims of a pack being able to charge, say, a Galaxy S8 or iPhone X six times over. Battery capacity and efficiency varies based on a number of factors. Read this Macworld report on USB-C packs to learn more about batteries and capacity.
• Look at the specs of the battery, and ensure that its input isn’t limited to slow charging such as 5V/1A. The faster the input, the faster your battery pack rechargers, the faster you’re ready to hit the road.