The beast among the 20k power banks: Cuktech 15 Ultra review

The Cuktech 15 Ultra is characterized above all by its Beast Mode. This enables up to 165 W fast charging of the power bank via the two Type-C ports. This means it can be charged from 0 to 70 percent in just over 20 minutes. This is particularly practical when a (reasonably fully charged) power bank is needed at short notice.

Otherwise, the Cuktech 15 Ultra offers more or less the same features as other power banks in the 20,000 mAh class. With a total of a good 160 W, two devices can be charged quickly. If only one USB-C port is used, up to 140 W is possible. We missed an integrated USB-C cable, which has proven to be extremely practical with various competitors.

Some of these are also a few grams lighter than the 15 Ultra from Cuktech, which weighs just under 600 g. However, at less than $80, it is remarkably affordable for the performance it offers.

The Cuktech 15 Ultra Powerbank is sold for $77.99 on Amazon. This means its recommended retail price is lower than that of many comparable power bank models with 20.000 mAh and 165 W.

There are many power banks with 20,000 mAh on the market. However, with the 15 Ultra, Cuktech offers a model that aims to stand out from the competition, especially with its so-called "Beast Mode". In this practical test, we explain what this means and what else the Cuktech 15 Ultra has to offer.

With a capacity of less than 100 Wh, the Cuktech 15 Ultra can be carried in hand luggage when traveling by air if the regulations of the respective airline allow this. However, only the CE and FCC markings are printed on it, not the 3C marking (CCC) required for flights to and within China.

The battery capacity is packed into a device that weighs approx. 590 g and measures around 15 x 5.5 x 4.5 cm. This makes the Cuktech 15 Ultra comparable in size to other power banks in this performance class. However, it is around 100 g heavier than the Anker Prime Powerbank (20K, 220W). So if you're traveling light and want to save every gram, you're better off with other mobile power banks, but you'll usually pay more than with Cuktech.

The Cuktech 15 Ultra also has a slight weight disadvantage compared to the Ugreen Nexode Powerbank with 20,000 mAh and 165 W, which is also slightly more expensive according to the MSRP. There is also another point of criticism of the test candidate in this duel. Cuktech has not integrated a USB-C cable into the 15 Ultra.

There is therefore neither an extendable USB-C cable nor a USB-C cable "disguised" as a wrist strap. This is a shame as, in my opinion, this is one of the most practical things about a power bank. Instead, you always have to rely on an external cable when using it. However, with a length of 1 m and up to 240 W, this is at least included in the scope of delivery, as is a small cloth bag to transport the power bank carefully.

There is little else to criticize when it comes to the connections. Two USB Type-C ports with up to 140 and 65 W respectively are up-to-date and sufficient to charge modern laptops and the like quickly. There is also a USB-A port that provides up to 18 W. If several ports are used at the same time, a maximum of 165 W is possible.

In practice, we didn't quite reach this with a good 160 W. However, this is still enough to quickly power two notebooks or a laptop and a smartphone at the same time via two Type-C ports. Thanks to the ADC 2.0 protocol, which supports numerous fast charging protocols such as PPS, QC, PD3.1, FCP, SCP and MiPPS, the power bank can be used in a variety of ways.

With an output power of 165 W, the Cuktech 15 Ultra is one of many power banks on the market. When it comes to charging the power bank itself, however, the model clearly stands out from many competitors - especially in "Beast Mode". This is activated by connecting sufficiently powerful chargers with at least 100 and 65 W respectively to USB-C ports 1 and 2.

For our hands-on, Cuktech provided its 100 W USB-C charger ($35.99 on Amazon) and the 65 W USB-C charger. Of course, the Cuktech 10 Ultra or any other chargers from other manufacturers can also be used.

Then the Cuktech 15 Ultra turns on the turbo and, in the test, fired up with over 150 W right from the start. After a good three minutes, the first 10 percent is in the tank, and in less than 10 minutes the display shows 30 percent. The 70 percent mark was reached in less than 23 minutes.

After that, however, the charging speed decreases significantly and was still just under 80 W in the practical test at 90 percent. This is also due to the fact that the power bank switches to single-port charging from 70 percent. The complete charging process from 0 to 100 percent was then completed in 44 minutes and 30 seconds in the test of the Cuktech 15 Ultra, which is still impressively fast.

If a power bank that is at least reasonably charged is needed at short notice, it is a practical way to turn an empty 15 Ultra into a full one within a short time. The charging time is definitely impressive, but probably does not necessarily contribute to the service life of the power bank, as the slight heating also shows. However, this can only be shown by long-term use, for which our test period was too short. However, we would advise you to usually do without Beast Mode.

Especially as the power bank does not charge that much slower in normal mode via USB-C1. If a sufficiently powerful charger is connected, a good 130 W flowed in the test. The 70 percent mark is then reached after around 27 minutes - i.e. only around 4 minutes slower. The complete charging process from 0 to 100 percent took well under an hour in the test, so not much longer than in beast mode.