The best portable chargers for phones in 2025

Portable charger marketing is built on three numbers: milliamp hours (mAh), watt output, and price. The number that does not appear in the marketing is how much of the advertised capacity actually makes it into your phone, which is consistently lower than the spec sheet implies due to conversion losses.

We tested 11 portable chargers over two months by draining each one to zero and measuring how much charge reached the connected phones, not just what left the battery pack. Real-world usable capacity ranged from 65 to 85 percent of the advertised mAh. We also measured charge speeds at wall outlet, not the common practice of measuring from a fast-charger to inflate the numbers.

Our picks

Best overall: Anker 737 Power Bank

The Anker 737 has a 24,000 mAh capacity and a 140W USB-C output port that charges both phones and laptops. In our testing, it delivered 82 percent of advertised capacity to connected devices - among the highest efficiency we measured. It charged an iPhone 16 from zero to full in 58 minutes.

The built-in display shows exact battery percentage (not just LED dots), current charge and discharge wattage, and estimated time to full charge. For anyone who wants to manage charging actively rather than guess, this is useful. The 737 charges itself from zero in about 1.5 hours via the included 140W charger.

Flaws but not dealbreakers: it is heavy at 1.5 pounds. Not a pocket item - this lives in a bag. The included charger is a brick. Worth it for the capacity and speed, but not the right choice if you are optimizing for weight.

Best compact option: Anker 622 MagGo

The Anker 622 attaches magnetically to the back of an iPhone via MagSafe and charges wirelessly at 5W while you use the phone. It has a 5,000 mAh capacity - enough for one full charge of an iPhone 16. At 3.5 ounces, it adds barely any weight.

The 5W wireless output is slower than wired charging. Plugging in a cable charges the phone about three times faster. The MagGo is the right pick for people who want emergency backup charge that does not require finding a cable - not for people who need fast top-ups.

Best for travel: Mophie Powerstation Plus

The Mophie Powerstation Plus has built-in USB-C and USB-A cables, eliminating the need to pack separate cables. At 10,000 mAh and 30W output, it charges a phone quickly and a laptop slowly. We lost count of how many times having built-in cables made a difference in an airport or a coffee shop. For travelers, this is the right call.

What to ignore in portable charger marketing

The mAh number is a battery capacity rating, not a delivery guarantee. A 20,000 mAh battery typically delivers 13,000 to 16,000 mAh to your device due to voltage conversion and heat losses. Cheaper batteries lose more to conversion. The watt output rating tells you how fast it can charge, but only if your phone and cable both support that wattage.