A heap of energy for a few bucks! The 30,000mAh Swissten power bank is half price

You should definitely consider this power bank on sale. Alza has now dropped the price of the Swissten Power Line II to 548 CZK from the original 1,090 CZK, exactly by half. You can check the current price and stock availability in detail on Alza.

Quick summary:
✅ Makes sense if you want a large capacity for a weekend without an outlet and to charge multiple devices at once.
⚠️ Consider that it charges slowly itself (users report around 8 hours) and at 603g, it’s not the lightest.
💡 For 548 CZK, it offers a lot of capacity, just expect roughly two-thirds to be actually usable.

Why this power bank is interesting

The main draw is clear: 30000 mAh is a reservoir with which you can charge your phone five times or spend a weekend at a festival without looking for an outlet. Plus, a display showing the remaining capacity, so unlike blinking LEDs, you know exactly where you stand. For 548 CZK, it’s a decent value, underscored by a low complaint rate of 0.38% across over a thousand units sold.

Key parameters explained simply

Let’s be honest about the numbers: from 30000 mAh, you’ll realistically use about 19,000–20,000 mAh at the output due to voltage conversion and losses. Still, that’s enough for several full phone charges. Three ports (2× USB-A, 1× USB-C) can charge three devices simultaneously, and the 22.5 W output is sufficient for a quick phone charge — but it’s not for laptops. One user summarized it concisely: “charges quickly”.

Practical aspects: weight, charging, ports

Large capacity comes with a trade-off in size. At 603g, it’s not a pocket-sized gadget — you won’t notice it in a backpack, but you won’t stuff it into your jeans, which one reviewer commented on by saying “it could be lighter”. And be aware that charging the power bank itself takes a long time; user Jakub reports around 8 hours, so ideally, charge it overnight. A cable is not included in the package; you’ll use your own USB-C.

What users say

Rated 4.3 out of 5 by 14 customers, 86% recommend it. People mainly praise its large capacity “for multiple phone charges”, the display, and its speed. However, it’s not all rosy: one customer writes that the power bank “stopped working after 15 days and started reporting error 188“. With a complaint rate under half a percent, this is likely an isolated incident, but it’s fair to mention it.

When it doesn’t make sense

If you want a pocket-sized power bank for a single daily charge, this one is unnecessarily large and heavy — opt for a compact model around 10000 mAh. And 22.5 W is not enough for charging a laptop; for that, you need a model with around 100 W of power. However, for weekend trips, festivals, and charging multiple devices at once, it’s ideal.

Verdict: who it’s worth it for

For 548 CZK, the Swissten Power Line II is an honest choice for anyone who wants a lot of power on the go and to charge multiple devices at once. The display, three ports, and low complaint rate make the half-price a very appealing argument. Don’t consider it a pocket-sized gadget or a power source for a laptop, but rather a reliable reservoir for the weekend. At this price, it won’t stay on the shelves for long.

Do you carry a large power bank for travel, or is a smaller pocket-sized model sufficient for daily charging?