A power bank might seem like a simple gadget—you plug it in, charge your device, done. But not all power banks are created equal. From capacity to safety, there are a few things you should know before you click “Buy Now,” especially if you want something reliable, travel-friendly, and actually worth your money.

Here are 7 key things to know before buying a power bank:

1. Capacity Matters (But Bigger Isn’t Always Better)

Power bank capacity is measured in milliamp-hours (mAh). The higher the number, the more charge it holds. A 10,000mAh power bank can typically recharge a smartphone 2–3 times. Need to charge tablets, laptops, or multiple devices? You might want 20,000mAh or more.

But keep in mind: higher capacity also means a bulkier device. If you’re just topping off your phone on the go, a smaller model might be all you need.

2. Pay Attention to Output Power (Wattage)

Not all power banks charge at the same speed. Look for output ratings in watts (W) or volts and amps (like 5V/2.4A). If you’re using a newer iPhone or Android, get a power bank with fast charging—at least 18W USB-C output.

Some power banks also support Power Delivery (PD) or Quick Charge (QC) protocols, which are essential for fast-charging devices like iPads, Switch consoles, or MacBooks.

3. Know Your Ports

USB-A, USB-C, micro-USB, Lightning—what you need depends on what you’re charging and how you’re recharging the power bank itself. Most modern power banks now use USB-C for both input and output, which is a plus.

Pro tip: Choose a power bank with at least two ports if you want to charge more than one device at once.

4. Weight & Portability Count

If you’re traveling or commuting, size and weight make a difference. Some high-capacity power banks are the size of a brick—not great for pockets or purses. For everyday carry, look for slim or mini models with at least 5,000–10,000mAh capacity.

5. Safety Features Are a Must

Overheating, overcharging, and short-circuiting are real risks with cheap, off-brand power banks. Stick to reputable brands that advertise safety features like overvoltage protection, temperature control, and battery cell certification (e.g., UL-certified). Don’t skimp when it comes to safety—especially if you’re charging expensive devices.

6. Air Travel Restrictions Apply

In the U.S., TSA allows you to bring power banks in carry-on bags only—not in checked luggage. Also, there’s a limit: they must be under 100Wh (which is about 27,000mAh). Always check the watt-hour rating (it’s usually printed on the device) before flying.

7. Wireless and Solar Sounds Cool—But Know the Trade-Offs

Wireless charging power banks are convenient but less efficient. Your phone must stay aligned on the pad, and charging is slower. As for solar power banks? Great for emergencies and camping—but don’t expect fast or consistent charging without strong sunlight.

Final Word

Buying a power bank isn’t just about grabbing the cheapest one on Amazon. Think about what you need it for, how often you’ll use it, and what devices you’re charging. A little research up front goes a long way toward avoiding disappointment—or a dead phone when you need it most.