Cuktech is a brand that may not be on your radar yet; it originated as a white-label manufacturer and merged with ZMI—part of Xiaomi’s extensive ecosystem—in 2022. Now, it’s striving for a global footprint with compelling product launches. Among them is the Cuktech 30, a hefty 40,000mAh power bank sporting a 300W power limit and Qi compatibility. The focus here is on the Cuktech 15 Ultra, which boasts a 20,000mAh capacity and a 165W power limit.
The Cuktech 15 Ultra retails for $87 on Amazon at the time of this writing, placing it in the higher price range, especially when you consider that UGREEN’s Nexode 20,000mAh Power Bank is priced at $59. Nevertheless, the build quality of this power bank is exceptional, rivaling even the Anker Prime 27,650mAh model—a significant achievement.
Before diving deeper, a note on the brand name: Cuktech derived its name from the Čuk DC-DC converter architecture, named after Slobodan Čuk. Now, let’s explore the design. Much like Anker and UGREEN, Cuktech opted for a vertical profile for the power bank, which enhances portability significantly.
The 15 Ultra boasts a sleek gray and black color scheme, enhancing its aesthetic appeal, while the textured back provides a secure grip. I have no complaints regarding its design; Cuktech has executed it exceptionally well.
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A button positioned at the front activates the display panel, where you can monitor battery life, charging time, and real-time metrics—all on a single screen. While it could be argued that separating real-time charging info onto a secondary page would reduce clutter, this is a minor critique since the display provides all necessary information.
Thanks to its 72Wh battery, the 15 Ultra is airline-approved for carry-on. With its 20,000mAh capacity, you can charge your phone multiple times, alongside several additional devices, and its charging efficiency aligns with recently tested brands.
That said, you can’t expect to charge a device with a 5000mAh battery four times with the 15 Ultra; the natural energy loss means its efficiency hovers just below 60%. Thus, you can reasonably anticipate around 12,000mAh of usable charge. This is consistent across all power banks, so the 15 Ultra offers comparable performance in this regard.
On a related note, the power bank features three ports—two USB-C and one USB-A. The primary USB-C port supports up to 140W with the USB PD 3.1 standard, while the secondary USB-C can deliver 65W, and the USB-A port is limited to 18W, suitable for accessories. When both USB-C ports are active, they can provide a combined output of 165W. Below, I outline the power profiles and how the 15 Ultra manages simultaneous charging:
- USB-C1 in/out (140W max): 5V/3A (15W), 9V/3A (27W), 12V/3A (36W), 15V/3A (45W), 20V/5A (100W), 28V/5A (140W)
- USB-C2 out (65W max): 5V/3A (15W), 9V/3A (27W), 12V/3A (36W), 15V/3A (45W), 20V/3.25A (65W)
- USB-A out (18W max): 5V/3A (15W), 9V/2A (18W)
- USB-C1 + USB-C2 out (165W max): 100W + 65W
- USB-C1 + USB-A (118W max): 100W + 18W
- USB-C2 + USB-A (83W max): 65W + 18W
- USB-C1 + USB-C2 + USB-A (163W max): 100W + 45W + 18W
In my experience, the 15 Ultra performed reliably while charging my Vivo X200 Pro, Find X8 Ultra, iPhone 16 Pro Max, and Pixel 9 Pro XL. It showed no signs of overheating, and Cuktech’s thermal management was commendable.
In conclusion, the 15 Ultra distinguishes itself through its refined design and dependable charging capabilities. While Cuktech is relatively new in global markets, it exhibits a clear understanding of what is essential in this field.
With a sleek design and excellent charging potential, the 15 Ultra fulfills all the needs of a 20,000mAh power bank.