Power Banks
Bottom line: Buy a 20,000mAh (about 74Wh) power bank with 65W USB-C PD if you travel or carry a laptop, and a 10,000mAh 30W unit for a daily phone top-up. Judge banks by watt-hours, not mAh alone, and confirm the USB-C port charges the bank as well as your devices.
Quick picks
- Daily phone top-up: 10,000mAh, 30W USB-C, slim enough for a pocket
- Travel and laptops: 20,000 to 26,800mAh with 65W+ USB-C PD
- Airplane-safe maximum: Under 100Wh (about 26,800mAh) for carry-on rules
What actually matters
| Spec | Why it matters | What to look for |
|---|---|---|
| Capacity (Wh vs mAh) | mAh is misleading across voltages; Wh is the real stored energy | Multiply mAh by 3.7 and divide by 1000 to get Wh |
| USB-C PD output | Decides charge speed and laptop support | 30W for phones, 45 to 65W for laptops |
| Recharge speed | A big bank is useless if it takes all day to refill | Look for 30W or higher USB-C input |
| Ports and display | How many devices and how much charge remains | Two outputs minimum; a digital percentage display is worth it |
| Pass-through charging | Charge the bank while it charges your device | Useful when you only have one wall outlet |
How to choose
- Commute and daily use — 10,000mAh is the best size-to-weight balance
- Flights and long trips — 20,000 to 26,800mAh stays under the 100Wh carry-on limit
- Laptop on the go — Requires 45W or 65W PD output, not just a high mAh number
Mistakes to avoid
- Choosing the biggest mAh without checking watt-hours and carry-on limits.
- Buying a 20,000mAh bank with slow 10W input that takes all night to recharge.
- Assuming every USB-C port outputs laptop power; many are output-only or low wattage.
- Ignoring weight when the bank will live in a pocket or small bag.
Frequently asked questions
How many times will a 10,000mAh bank charge my phone?
Roughly one and a half to two full charges after conversion losses, depending on your phone battery size.
Can I bring a power bank on a plane?
Yes, banks under 100Wh (about 26,800mAh) are allowed in carry-on baggage. Check your airline for the exact rule.
What does 65W PD mean on a power bank?
The USB-C port can negotiate up to 65 watts of output, which is enough to charge many laptops.
Does a power bank lose charge when not used?
Yes, all banks self-discharge slowly. Store it around half charge and top it up every few months.
What is pass-through charging?
Charging the power bank from the wall while the bank simultaneously charges another device.
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