Choosing a power bank for travel means balancing enough capacity to keep your devices running with the airline rules that limit battery size and require spare batteries in carry-on luggage. You also want fast charging for phones, tablets, and possibly a laptop, all in a package that isn’t too heavy or bulky. This guide walks you through the key factors so you can pick a power bank that works for your trip.
Airline Rules in Brief
The Federal Aviation Administration (FAA) and Transportation Security Administration (TSA) have clear rules for lithium-ion power banks. Spare power banks (not installed in a device) must be carried in your carry-on luggage only. They are not allowed in checked baggage. The rating must be at or under 100 watt-hours (Wh) for most power banks. If a power bank is between 100 Wh and 160 Wh, you may be allowed to carry it with airline approval, but many travelers find it simpler to stay at or under 100 Wh. Always check the manufacturer’s label for the Wh rating. For the latest official guidance, refer to the FAA PackSafe page on lithium batteries and the TSA What Can I Bring page.
Understanding mAh and Wh
Power bank labels show two numbers: milliampere-hours (mAh) and watt-hours (Wh). mAh tells you the charge capacity at the battery’s internal voltage (typically 3.7V for lithium-ion). Wh is the total energy capacity and is the number airlines use. To convert mAh to Wh, multiply by the voltage (3.7V) and divide by 1,000. For example, a 20,000 mAh power bank at 3.7V equals about 74 Wh (20,000 × 3.7 / 1,000). A 27,000 mAh power bank at 3.7V equals roughly 100 Wh. Most travelers stick with power banks at or under 27,000 mAh to stay within the 100 Wh limit. Always check the Wh printed on the label rather than doing the math yourself.
Choosing the Right Capacity
How much capacity you need depends on what devices you carry and how often you can recharge the power bank.
For Phones
A typical smartphone battery holds around 3,000–5,000 mAh. A 10,000 mAh power bank typically recharges a phone about one and a half to two times, because some energy is lost in conversion. For a long day out or a full travel day, 10,000 mAh is often sufficient. If you use your phone heavily for navigation, streaming, or tethering, consider 15,000–20,000 mAh.
For Tablets
Tablets have larger batteries, often 7,000–12,000 mAh. A 10,000 mAh power bank may give a partial charge, while 20,000 mAh can fully charge most tablets once or twice. If you plan to watch movies or work on a tablet during a long flight, a 20,000 mAh power bank is a good match.
For Laptops
Laptops require much more energy. A typical ultrabook battery is around 40–60 Wh (roughly 11,000–16,000 mAh at 3.7V, but laptop batteries operate at higher voltages). To fully charge a laptop, you often need a power bank with at least 20,000 mAh (around 74 Wh) and one that supports USB-C Power Delivery (PD). Many travelers choose a 26,800 mAh (about 99 Wh) power bank to stay just under the airline limit while having enough capacity for a full laptop charge plus some phone charging.
| Device Type | Typical Battery Size | Recommended Power Bank Capacity (mAh) |
|---|---|---|
| Smartphone | 3,000–5,000 mAh | 10,000–20,000 |
| Tablet | 7,000–12,000 mAh | 15,000–20,000 |
| Ultrabook Laptop | 11,000–16,000 mAh (equivalent) | 20,000–26,800 |
USB-C Power Delivery (PD) for Faster Charging
USB-C Power Delivery (PD) is a fast-charging standard that allows higher power transfer, up to 100W or more. For travel, a power bank with USB-C PD is essential if you want to charge a laptop quickly. Many modern phones and tablets also support PD for faster charging. Look for a power bank that lists its USB-C output in watts (e.g., 45W or 60W). A 45W output is enough for most ultrabooks; a 60W or 100W output can charge larger laptops. When shopping, consider USB-C power banks that include a USB-C cable or have a built-in cable for convenience. Also check that the power bank supports bidirectional charging — that is, the USB-C port can both charge the power bank and output power to devices.
Size and Weight Considerations
Capacity directly affects size and weight. A 10,000 mAh power bank is compact and light, fitting easily in a pocket or small bag. A 20,000 mAh unit is larger, roughly the size of a smartphone but much thicker and heavier. A 26,800 mAh power bank (just under the airline limit) is noticeably bigger and heavier, often comparable to a paperback book. For a carry-on only trip, you have to decide how much weight you are willing to carry. If you travel with just a backpack and only need to top off a phone, a smaller power bank is fine. If you rely on a laptop for work and want a full charge, the larger size may be worth the weight. Some power banks also come in a slim, rectangular shape that packs more easily than a bulky cube.
Pass-Through Charging
Pass-through charging lets you charge the power bank itself while it simultaneously charges your connected devices. This is useful when you have limited wall outlets, such as in an airport lounge or on a plane (if the seat has a power port). Not all power banks support pass-through charging, and those that do may have slower charging speeds or generate more heat. Check the manufacturer’s instructions to see if pass-through charging is supported and whether it is safe. If you plan to use this feature, look for a power bank that explicitly lists pass-through capability and has adequate thermal protection. Some airlines restrict using or charging power banks during the flight, so check your airline’s rules before relying on seat power to top one up.
FAQ
Can I bring a power bank on a plane?
Yes, but only in your carry-on luggage. Spare lithium-ion batteries and power banks are prohibited in checked baggage. The power bank must be rated at or under 100 watt-hours (Wh). If it is between 100 and 160 Wh, you need airline approval. Always check the label for the Wh rating.
How do I know if a power bank is safe to use on a plane?
Check that the Wh rating is clearly printed on the power bank. Follow the FAA guidelines: do not pack it in checked luggage, and if the power bank is damaged or swollen, do not bring it. Also, avoid using a power bank while it is charging from the seat power if the manufacturer warns against pass-through charging. Refer to the FAA PackSafe page for details.
What is the difference between mAh and Wh?
mAh (milliampere-hours) measures charge capacity at the battery’s internal voltage (typically 3.7V). Wh (watt-hours) measures total energy and is the number used for airline limits. To convert: Wh = mAh × 3.7 / 1,000. Always rely on the printed Wh rating rather than calculating yourself.
Do I need a power bank with USB-C PD for my laptop?
If your laptop charges via USB-C, yes. USB-C Power Delivery (PD) provides the higher wattage needed to charge a laptop effectively. Without PD, a standard USB-A port may not supply enough power. Look for a power bank that outputs at least 45W for most ultrabooks, and check that your laptop supports charging via USB-C.
Choosing the right travel power bank comes down to knowing your devices and the airline rules. Stick with a capacity that meets your needs without exceeding 100 Wh, prioritize USB-C PD if you carry a laptop, and consider size and pass-through charging for convenience. For more travel gear advice, see our guide on how to choose a universal travel adapter and our recommendations for noise-canceling headphones for travel to complete your travel kit.
