Xiaomi Redmi 20000mAh
(17 reviews)
20000 mAh, 18 W fast charging and dual USB output to charge two devices: several days of backup power at a rock-bottom price, by Redmi.
Characteristics
- Capacity: 20000 mAh (74 Wh)
- Power: 18 W (fast charge)
- Ports: 2 USB-A output, micro-USB and USB-C input
- Weight: About 434 g
- 20000 mAh and 18 W charging at a tiny price
Detailed overview: Redmi 20000 mAh power bank 18W
The Redmi 20000mAh 18W Fast Charge rests on a simple equation: a big 20000 mAh capacity, 18 W fast charging and a tiny price. It is the go-to battery for anyone who wants autonomy without breaking the bank, able to last several days away from a socket.
Its 20000 mAh (74 Wh) recharge a modern smartphone about four times, or noticeably extend a tablet's runtime. It has two USB-A output ports, so you can charge two devices at once, and its 18 W fast charge (Quick Charge compatible) quickly tops up a recent phone. For refuelling, it accepts two inputs, micro-USB and USB-C, so you can recharge it with whichever cable is at hand.
A four-step LED indicator shows the remaining level. The plain, sturdy casing weighs about 434 g: not the lightest, but the logical trade-off for such a large reserve at this price. It slips easily into a backpack, a bag or a glovebox.
Its limits match its positioning: fast charging tops out at 18 W, plenty for phones and tablets but not for a demanding laptop, and there is no USB-C output (the USB-C is only for recharging it). But for a reliable, roomy and genuinely affordable backup battery, the Redmi 20000mAh remains a safe choice, ideal for travel, festivals or simply never running flat.
Full specifications
Detailed characteristics
Battery
| Rated capacity?Cell capacity in milliamp-hours, as stated by the manufacturer. | 20000 mAh |
|---|---|
| Actual energy?Actual stored energy in watt-hours; what matters for runtime and air travel (100 Wh cabin limit). | 74 Wh |
| Delivered energy, measured?Energy that actually leaves the battery and reaches the devices. Always below the stored energy, as conversion costs heat. Taken from our in-depth review. | 61 Wh |
| Battery chemistry?Cell type; LFP lasts longer, Li-ion/LiPo is lighter. | Li-ion |
Output (device charging)
| Max output power?Maximum total power delivered; above 60 W it can charge a laptop. | 18 W |
|---|---|
| USB-A ports?Number of USB-A ports and maximum power. | 2 × 18 W |
| Fast-charge protocols?Supported fast-charge standards (PD, QC, PPS…); PD/PPS is the most universal. | QC 3.0 |
| Wireless charging (Qi)?Inductive charging of a phone placed on top, and its power. | No |
| Magnetic attachment (MagSafe)?Attaches magnetically to the back of a MagSafe-compatible iPhone. | No |
Recharging the power bank
| Recharge power (input)?Maximum input power to recharge the power bank; higher means faster. | 18 W |
|---|---|
| Pass-through charging?Can charge a device while being recharged itself (pass-through). | Yes |
Cable and interface
| Built-in cable?A cable is permanently attached to the power bank (nothing extra to carry). | No |
|---|---|
| Retractable cable?The built-in cable retracts into the housing. | No |
| Cable included?A cable is included in the box. | Yes |
| Display?Level display: simple LED indicators or a digital screen (%, watts). | LED indicators |
| LED light?Built-in LED torch / light. | No |
Form factor
| Weight?Weight of the power bank, in grams. | 15.3 oz (434 g) |
|---|---|
| Dimensions (L × W × D)?Length × width × depth, in millimetres. | 6.1 × 2.9 × 1.1 in (154 × 73.6 × 27.3 mm) |
Availability and warranty
| Market launch?Date the model first became available on the European market. Useful to place its generation: technology moves fast in this segment, and a device several years old may be at the end of its commercial life. | July 2019 |
|---|
⚡ How many charges with this power bank?
With 74 Wh of capacity, the Xiaomi Redmi 20000mAh power bank recharges iPhone 16 ~3.9 times or Samsung Galaxy S25 ~3.5 times.
| Smartphone | Charges |
|---|---|
| iPhone 15 | ~4.1 |
| iPhone 14 Pro Max | ~3.2 |
| Nothing Phone 3 | ~2.7 |
| Xiaomi 17 Pro Max | ~1.8 |
| Tablet / console | Charges |
|---|---|
| Nintendo Switch OLED | ~3.3 |
| Nintendo Switch 2 | ~2.7 |
| Asus ROG Ally | ~1.3 |
| Asus ROG Ally X | ~0.7 |
Rough estimate: real-world losses (conversion, cable, heat) are around 25 to 35%.
Comparison
How does the Redmi 20000mAh stack up against other 20000 mAh batteries?
| Criterion | Redmi 20000mAh 18W | Anker 335 (20000) | INIU 20000 22.5W |
|---|---|---|---|
| Capacity | 20000 mAh | 20000 mAh | 20000 mAh |
| Power | 18 W | 20 W | 22.5 W |
| USB-C output | No (input only) | Yes | Yes |
| Price | Rock-bottom | Mid | Mid |
The Redmi clearly plays the price card: it is often the cheapest of the lot, with a big capacity and honest 18 W charging. The Anker 335 and INIU offer a USB-C output and slightly higher power, useful if you charge a device over USB-C, but at a higher price. For budget smartphone top-ups, the Redmi is hard to beat.
Related video
Video: Redmi 20000 mAh Power Bank Review - 18W Fast Charging - Published on 17/04/2022
Our tester's review: Guillaume Hoarau
For under 15 pounds, the Redmi 20000mAh is one of those accessories you buy without a second thought. I have hauled it on weekends, at festivals and in my travel bag: it recharges my phone three to four times, enough to forget the charger for two days. The two USB-A outputs are handy for helping out a friend while charging your own device. The 18 W fast charge does the job on a smartphone, even if you can tell it is not the latest 65 W standard. The minor gripes: it is a bit heavy (434 g) and thick, and the USB-C is input only, not an output, which feels a little dated today. Nothing dealbreaking given the price. For a reliable, affordable energy reserve, it is a safe bet I recommend without hesitation.
In-depth review Redmi 20000mAh 18W: our full review 3.8/5 Read our full review → Capacity and runtime 3.9 Output power 3.7 Size and weight 3.7 Ports and cables 3.6 Recharging 4.2 Build and endurance 3.5Frequently asked questions: Redmi 20000 mAh power bank 18W
Its 20000 mAh (74 Wh) recharge a modern smartphone about four times, or extend your devices' runtime by several days away from a socket.
Yes, it has two USB-A output ports, so you can charge two devices simultaneously. The power is then shared between the two ports.
Yes, it has a USB-C input and a micro-USB input for recharging. However, the USB-C port does not deliver power as an output: the outputs are USB-A only.
Yes. At 74 Wh it stays under the 100 Wh threshold and can travel in the cabin with no special formality, like most power banks. It must stay in your hand luggage.
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Published on 02/09/2026