Can a power bank charge a laptop at full speed?

Only if the power bank's USB-C output matches or exceeds your laptop charger's wattage. A 100W power bank charges a MacBook Air at full speed (30W) but charges a MacBook Pro 16-inch slower than its 140W wall charger.

How many laptop charges does a power bank provide?

A 100Wh power bank provides roughly 1-1.5 charges for a MacBook Air (52.6Wh battery) or about 0.6-0.8 charges for a MacBook Pro 16 (100Wh battery). Real-world is ~80% of theoretical due to conversion loss.

Best Power Banks for Laptops 2026