In this guide 7 sections
Power banks are the most mis-sold gadget in Bangladesh. The capacity on the box is the capacity of the cells inside, not what reaches your phone — and the "fast charging" sticker is meaningless unless the port, the cable and your phone all agree on a standard. This guide gives you the handful of numbers that matter.
Real capacity: divide the label by about 1.5
A 10,000mAh bank stores its energy at 3.7 V and delivers it at 5 V or higher; conversion loses roughly a third. In practice a 10,000mAh bank refills a phone with a 5,000mAh battery about one and a half times, and a 20,000mAh bank about three times. If a seller claims a 10,000mAh bank charges your phone "four times", walk away.
Speed: match the standard, not the watts
Three things have to line up:
- The bank's output standard — USB Power Delivery (PD) is what modern Android phones, iPhones and laptops use; Quick Charge (QC) is older and Android-only.
- The cable — a cable rated below the bank's output silently throttles it. A 60W-rated Type-C cable such as the GearUP CC6015 covers any phone and most laptops.
- The phone — most phones top out at 18–33 W from a power bank regardless of what the bank can push.
For a phone, 20 W PD is plenty. 45 W or more, like the QCY PB20A, only earns its keep if you also charge a laptop or tablet, or want the bank itself to refill quickly.
Capacity by how you use it
| You | Buy | Why |
|---|---|---|
| Commuter, one phone | 10,000mAh, 20 W | Pocketable, a full day of top-ups, under airline limits |
| Load-shedding at home, two phones | 20,000mAh, 20–45 W | Three refills, charges two devices at once |
| Laptop user, travel | 20,000–30,000mAh, 45–65 W | Powers a USB-C laptop; e.g. the Hoco DB81 |
Flying with a power bank
Airlines allow power banks in cabin baggage only, generally up to 100 Wh (about 27,000mAh at 3.7 V). A 30,000mAh bank is over the limit on most carriers; a 20,000mAh one is fine. Keep the printed capacity label intact — security checks read it.
The signs of a good bank
- Capacity in both mAh and Wh printed on the body.
- Weight that makes sense: a real 20,000mAh bank weighs around 350–450 g. Light ones are lying.
- Type-C in and out; a display showing percentage rather than four LEDs is a bonus.
- Pass-through charging if you want to charge the bank and your phone together.
Making the battery last
Power bank cells wear out by cycle and by heat. Three habits roughly double their useful life: do not leave the bank in a hot car or on a sunny windowsill, recharge it when it drops to about 20% rather than running it flat, and top it up once a month if it sits unused in a drawer. A bank that has not been charged for six months may refuse to wake up at all — that is the protection circuit, not a fault, and a few minutes on a wall charger usually revives it. Expect a well-treated bank to hold around 80% of its original capacity after two years.
Charger first, bank second
Most people's slow charging has nothing to do with the bank. A proper wall charger — a 45 W GaN unit such as the GearUP GP007 — refills a power bank in a couple of hours instead of overnight and charges the phone directly when you are home. Pair it with a rated cable and the bank becomes a backup rather than your main charger.
See every option on the power banks, chargers & cables shelf, with cash on delivery across Bangladesh and a 7-day easy return on faults.
Frequently asked questions
How many times does a 10,000mAh power bank charge a phone?
About one and a half times for a phone with a 5,000mAh battery, because of conversion losses. A 20,000mAh bank gives roughly three charges.
Which is better for a power bank, PD or QC?
PD (USB Power Delivery). It works with iPhones, modern Android phones and laptops. QC is older and Android-only. Many banks support both.
Can I take a 20,000mAh power bank on a plane?
Yes, in cabin baggage — 20,000mAh is about 74 Wh, under the usual 100 Wh limit. 30,000mAh banks are over it on most airlines.
Why does my power bank charge my phone slowly?
Usually the cable. A cable rated under the bank's output throttles it; use a 60W-rated Type-C cable and make sure the phone itself supports PD or QC.
Do you deliver power banks outside Dhaka?
Yes — cash on delivery to every district, with a 7-day easy return on anything faulty.
