SUPER DUPER FAST CHARGING. EVEN MY HP LEFT WITH 1% OF BATTERY WITH THIS SAMSUNG POWERBANK 20000mah IT DOEST NOT REQUIRED A LOT OF TIME TO FULLY CHARGING MY PHONE. REALLY RECOMMENDED TO THOSE WHOSE HP EASILY HAVE FLAT BATTERY EVERY TIME WHEN GOING OUTDOOR. BASED ON MY EXPERIENCE IT CAN CHARGED MORE THAN 2 TIMES FOR FULLY CHARGED HP. FURTHERMORE IT CAN EASILY CARRIED AROUND BECAUSE IT ONLY 150G COMPARED TO OTHER POWERBANK WHICH MORE HEAVIER. RECOMMEND AS SUPER DUPER GOOD POWERBANK.