It has a huge capacity and built-in cables. The Swissten Voltbox power bank is discounted by over 500 CZK

You have the power bank in your backpack, but the cable stayed at home on the table. Swissten Voltbox solves this problem in its own way – it carries the cables directly in its body. With code ALZADNY15, you can now buy it on Alza for 790 CZK, even though at the beginning of October, the store wanted 1,299 CZK for it.

Quick summary:
✅ Makes sense if you want a large power bank for travel that can charge both Android and older iPhones without extra cables.
⚠️ Consider that it weighs 432 grams and you can usually only take it on a plane with the airline’s consent.
💡 For 790 CZK, Alza has not sold it cheaper according to HlídačShopů – it was only equally cheap briefly on October 9.

From 1,299 CZK down to 790 CZK

At the beginning of October, the power bank cost 1,299 CZK on Alza and was sold for this amount for most of this year. Now the store offers it for 929 CZK, and with the discount code ALZADNY15, at the time of writing, you will pay only 790 CZK, which is 509 CZK (approximately 39%) less.

It should be added how Alza itself handles the price. It now states 929 CZK as the regular price from which it calculates the discount with the code. However, according to the HlídačShopů service, the power bank has not been commonly sold for 929 CZK until now – for a significant part of the year, it remained at 1,299 CZK.

Two built-in cables and up to 35 W for phone and tablet

The main draw is the two integrated cables. The USB-C connector will serve newer iPhones and practically all Android phones, while Lightning is suitable for iPhone 14 and older models. According to the manufacturer, the USB-C cable and the standalone USB-C port will deliver up to 35 W, Lightning can handle 27 W, and the classic USB-A port 22.5 W. There are thus four outputs in total, so you can charge multiple devices simultaneously.

The 30,000 mAh capacity is enough for several phone charges, and with 35 W, the power bank can also handle a tablet or a smaller laptop. It will be appreciated by, for example, a family where one person has an iPhone with Lightning and the other an Android, or anyone going on a long weekend camping trip or a long train journey with both a phone and a tablet. The remaining energy is shown in percentages on the display, and thanks to the pass-through function, you can charge the power bank and simultaneously charge your phone from it.

Customers praise the cables, some complain about the capacity

On Alza, the power bank has 4.8 out of 5 stars from 71 ratings, 94% of customers recommend it, and over 5,000 units have been sold. Reviews repeatedly highlight the built-in cables and long endurance – according to one customer, it charged a phone with a 5000mAh battery almost from zero six times. Alza also reports a low complaint rate of 2.05%.

Two reviewers, on the other hand, complain that the capacity is lower than what the box promises. This is partly due to physics – the 30,000 mAh figure refers to the cell voltage of 3.85 V. Converted to 5 V from USB, this amounts to approximately 23,000 mAh, and that’s before conversion losses. Some also note that the USB-C connector on the built-in cable fits very tightly.

432 grams and only with permission on a plane

Large capacity comes at a price. The power bank measures 12 × 7.6 × 3.7 cm and weighs 432 grams, so you’ll hardly fit it into a trouser pocket. Furthermore, the manufacturer states an energy of 115.5 Wh, which is above the usual airline limit of 100 Wh – you can usually only take it in carry-on luggage with the airline’s consent, and power banks are not allowed in checked luggage at all.

Also, expect longer charging times for the power bank itself: the USB-C input can handle a maximum of 30 W, so a full charge can take several hours. And for those who mainly need one phone charge per day, a smaller and lighter power bank will suffice, such as the 10,000mAh version of the Voltbox. You can find more tips in our overview of best-selling power banks.

At 790 CZK, it’s worth it mainly for travel

The Swissten Voltbox is a heavier, but practical power bank for those who don’t want to deal with cables – typically for holidays, a cabin without electricity, or business trips where you don’t want to search for a cable. For 790 CZK with code ALZADNY15, you can now get it for 509 CZK less than at the beginning of the month. Anyone who flies frequently or wants to carry a power bank in their pocket should rather opt for a smaller model.

Would you trade a lighter power bank for one that always has cables at hand?