The south-west of Berlin had to make do without electricity for days. And even when the power is back on, a charged powerbank is worth its weight in gold in an emergency. Stiftung Warentest tested 24 power banks with prices ranging from just under 30 to around 100 euros. The practical test confirms this: All of them can charge compatible laptops as well as smartphones and tablets...

Charging capacities that are too low, exaggerated wattage figures (which only result in ideal combinations), losses during charging: It's amazing how many weaknesses can arise in a supposedly simple product like a power bank. Good thing we tested it. The test winner Ugreen Nexode 165W can charge two notebooks and a mobile phone in parallel, wastes little power when charging and manages to fully charge...