ZenFone 2 built-in 3000mAh capacity battery, if with fast charge charger, charge 39 minutes up to 60% of capacity. what are the indicators of fast charging? ASUS Zenfone Blog will show you the indicators.
- Fast Charging Adaptor output is 2A
Top: Zenfone 2 Fast Charging, Bottom: Asus Zenfone 5 Adaptor - Lightning + logo at Status bar
Normal Charging 
Fast Charging Boostmaster - Lockscreen Information
Normal Charging 
BoostMaster Fast Charging
