Power bank buying guide: comparison and advice

A power bank is chosen primarily by its storage capacity, which determines how many times you can recharge your devices. The number of devices you can charge simultaneously and the weight directly affect everyday practicality.

What to check

Storage capacity Capacity, measured in milliampere-hours, indicates how much energy the battery can store. It determines how many times you can recharge your devices before needing to recharge the battery itself. Current market models range from five thousand to twenty thousand milliampere-hours, with a median of ten thousand. The bar displayed on each product page lets you assess this capacity: the longer it is, the more autonomy you have. An average smartphone requires approximately three thousand milliampere-hours for a full charge. Market median: 10,000 mAh

Simultaneous devices This criterion counts the number of available ports for charging multiple devices at once. The simplest batteries offer only one port, while the most equipped models provide up to four. The median stands at two ports. The rating bar reflects this capability: the longer it is, the more devices you can plug in simultaneously. This characteristic becomes decisive if you travel with several people or regularly use a smartphone, earbuds and smartwatch during the same day. Market median: 2.5

Weight and portability Weight varies considerably depending on capacity and technology: from one hundred and seventy grams for the lightest models to over five hundred grams for the heaviest. The median sits at two hundred and forty-five grams. The displayed bar rates this criterion by favouring lightness: the longer it is, the easier the battery will be to slip into a bag or pocket. Bear in mind that high-capacity batteries are naturally heavier. You therefore need to balance autonomy against ease of transport according to your usual travel patterns. Market median: 209.5 g

Compatibility and cables Check that the output ports match your device cables. Some batteries integrate multiple connector types, others require you to provide your own cables. The input port for recharging the battery itself also matters: favour a standard you already use to limit the number of cables to carry. Also consider the battery’s recharge time, which varies depending on the supported input power.

Benchmarks based on 40 recent market listings, collected on 1 November 2026.

What you get for each budget

Under €20

Entry-level batteries generally offer limited capacity around five thousand milliampere-hours, a single output port and reduced weight, sufficient to rescue a smartphone once.

€20 to €50

This range provides capacities around the median of ten thousand milliampere-hours, often two simultaneous ports and a satisfactory balance between autonomy and weight for regular use.

Over €50

Premium models reach twenty thousand milliampere-hours or more, offer up to four simultaneous ports, but naturally weigh more to deliver this extended autonomy.