Which Power Bank Should You Buy?
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Quick answer
10,000mAh is the sweet spot for most people — roughly one and a half phone charges, still pocketable, and under the usual airline cabin limit. Make sure it has USB-C Power Delivery for both input and output; older micro-USB-input banks take most of a day to recharge themselves.
Is this you?
- Your phone doesn't last a full day out
- You travel and can't rely on finding a socket
- Your existing power bank takes forever to recharge
What actually matters
1.Printed capacity is not usable capacity
Voltage conversion loses energy, so a 10,000mAh bank delivers roughly 6,000–7,000mAh to your phone. That's normal physics, not a faulty product — but it means the marketing number always overstates what you get.
2.Bigger means heavier, fast
20,000mAh roughly doubles the weight and bulk of 10,000mAh. Most people who buy the larger one end up leaving it at home.
3.Input speed decides how usable it is
A bank with USB-C PD input recharges in a couple of hours. One with only micro-USB input can take eight or more, which makes it far less practical day to day.
4.Airline limits are real
Lithium batteries have to travel in the cabin and there's a watt-hour limit. 10,000mAh and 20,000mAh units are normally fine; very large capacities can be refused.
5.Cheap units overstate capacity
At the bottom of the market, printed capacities are often simply wrong. This is the main reason to buy from an established brand here.
How to choose
Work out how many charges you actually need
One top-up during a day out, or two full charges across a weekend? The answer usually points at 10,000mAh rather than something larger.
Check for USB-C PD in and out
Both matter. PD output charges your phone fast; PD input means the bank itself is ready again quickly.
Check the output wattage
18W or higher is worth having. Below that you're trickle-charging, which defeats the point when you're out.
Check whether it can pass through
Some banks can charge a device while being charged themselves. Convenient if you only have one socket.
What you'll want on hand
- A USB-C cable rated for the output you want
Recommended products
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Best Value
The balance most people should pick
10,000mAh USB-C Power Bank
Power bank
The capacity most people actually carry rather than leave at home, and comfortably within normal airline cabin limits.
Best for: A day out without a plug
See the full breakdownShopee
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Lazada
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Common questions
Why does my 10,000mAh bank only charge my phone 1.5 times?
Conversion losses. Around 60–70% of the printed capacity reaching your device is normal and expected across all brands.
Can I take it on a plane?
In cabin baggage, yes, for typical 10,000mAh and 20,000mAh units. Never in checked luggage. Very high capacities may need airline approval.
Is wireless charging on a power bank useful?
It's convenient and noticeably less efficient — you'll get fewer charges out of the same capacity. Useful as a bonus, not as the main reason to buy one.
How long do they last?
Two to three years of regular use before capacity drops noticeably. Leaving one fully flat or fully charged in a hot car for long periods shortens that considerably.