It depends on the charger you're using with. If you charge the powerbank with an 18W TurboPower charger it can fully recharge in roughly 3hrs from empty (it gets to 80% in 2hrs). For comparison, if you use with a 10W charger (which is what most 10,000mAh portable chargers recharge at), it takes just under 5hrs to fully recharge and just under 4hrs to reach 80%.