Review: Kuxiu S3 vs S4 10000 mAh Qi2.2 power banks

Review samples provided by Kuxiu

The Kuxiu S3 and Kuxiu S4 are wireless power banks with 10,000 mAh battery capacity and support Qi2.2 with charging speed that supposedly go up to 25W. Prices for the Kuxiu S3 and S4 are USD 63 and USD 85 at the time of review.

Kuxiu S3 is thicker and heavier at 245g, compared to Kuxiu S4 which is 215g. The difference with weight is not that different. Both power banks are well made.

The charging surface of Kuxiu S3 feels rubberised or like silicone. I've used this power bank for several months already and that surface still holds up well and did not become sticky. The Kuxiu S4 charging surface is matte textured plastic, quite susceptible to fingerprints.

Kuxiu S3 (right) has a built-in USB-C cable which is incredibly convenient. Kuxiu S4 has a USB-C to USB-C cable provided but you have to remember to bring that out if you want to use cable charging.

Both power banks support Qi2.2 but unfortunately you won't be getting anywhere near the advertised 25W wireless charging speed. I tested both power banks with the Samsung S26 Ultra and only measured 6W+ wireless charging speed. Even though the phone can detect fast charging, the charging speed is just not fast. iPhone wireless charging speed is better but still not as fast as cable.

Cable charging speed from the Kuxiu S3 and S4 are both above 30W, which is at least 4 times faster than wireless. And there's less energy loss due to better efficiency of cable charging. 30W charging may not be fast enough to charge laptops that require minimum wattage.

Both power banks have advertised 10,000 mAh battery capacity. However the rated battery capacity for the Kuxiu S3 is 6,500 mAh and for the Kuxiu S4 is 5,600 mAh. So the Kuxiu S3 actually has 16% more rated battery capacity. Both power banks are definitely able to charge a phone to full, and a tablet to almost full.

These power banks are MagSafe compatible and work best with iPhones. If you want to use a phone case, get a phone case that supports MagSafe. The MagSafe magnets from the power banks are strong.

Samsung phone has long camera bumps and that affects the position of the power bank. Power banks have to be aligned properly to get the best charging speed.

Both power banks have built-in stands that can deploy vertically and horizontally. Kuxiu's S3 kickstand is easier to deploy as there's more space for your finger to pull the kickstand out. Kuxiu S4 requires you to have some fingernail to pry out the kickstand.

There are displays on both power banks. Kuxiu S3's display only shows battery life in percentage. Kuxiu S4's display can show battery health, battery life in percentage, charging speed, and temperature.

Conclusion

The Kuxiu S3 provides more value for money. It has higher rated battery capacity, comes with a convenient build-in USB-C cable, kickstand is easier to deploy and is USD 20 cheaper. Downside is it's heavier compared to the Kuxiu S4 but it's not that much heavier.

Availability

The Kuxiu S3 and Kuxiu S4 are both available from the Kuxiu online store.