Power Banks

Power banks — how to choose the right capacity and wattage

A power bank is a portable battery with lithium-ion cells that charges your smartphone, tablet or laptop via USB-C. Key specs are capacity (mAh), charging power (W) and ports (USB-C PD, USB-A QC).

Capacity — how many times will it charge my phone

• 10,000 mAh — 1.5–2x smartphone, weighs 200–300 g, fits in a pocket
• 20,000 mAh — 3–4x smartphone, weighs 350–500 g. The most popular choice
• 30,000 mAh — 5–6x smartphone, also charges laptops with PD 65 W, weighs 500–700 g
• 50,000 mAh — 8–10x smartphone, weighs over 800 g. For a backpack, not for planes

Charging power — how many watts do you need

• 18–22.5 W — sufficient for a smartphone and earbuds
• 30–45 W — fast tablet charging
• 65–100 W (PD) — charges USB-C laptops (MacBook, Dell XPS, ThinkPad)

Special use cases

• MagSafe — magnetic power banks for iPhone, wireless charging through the back of the phone
• For planes — models compliant with IATA regulations (up to 100 Wh without airline approval)

Brands at homescreen.pl

Baseus — the widest selection, from MagSafe to PD 65 W models with LED display. Joyroom and Dudao — solid models at affordable prices. Usams and Romoss — budget options with large capacity. Ugreen — premium with USB-C PD. Tech-Protect — Polish accessories. Samsung and Spigen — branded, limited models. Mophie — premium MagSafe.

mAh vs Wh — when it matters

Capacity in mAh is a popular metric, but IATA regulations use Wh (watt-hours). Formula: Wh = mAh × V / 1000. At the standard voltage of 3.7 V: 10,000 mAh = 37 Wh, 20,000 mAh = 74 Wh, 27,000 mAh = 100 Wh (IATA limit without approval).