The handset usb power pack conversion rate is calculated by

Recent online users are asking: my 5000mah usb power pack how to iphone4 can charge twice ah! Iphone4 friends all know 1420 mA lithium battery Logically speaking 5000mah mobile power can charge iphone4 3.5 ah! How the two are not ah! This mobile power really pit father ah! In fact, many of my friends do not know how to calculate the conversion rate of mobile power. We usually say that the mobile power battery charger capacity refers to the capacity of the batteries. Mobile power board power is consumed in the process of moving power to charge the phone, the adapter is also power consumption, while the phone itself is also power consumption! Commonly referred to as a mobile power conversion rate = (actual discharge capacity * average discharge voltage) / (actual battery capacity * battery voltage). Phone battery standard voltage of 3.7V, mobile power batteries standard voltage of 3.7V. Many people will this voltage is ignored! To be considered in the calculation of the notebook when the voltage of the batteries. The notebook's battery voltage is 14.8V, 19V range! (Will not elaborate here elaborate next time!) The actual discharge amount is to say the power of its release of electricity, not the end handsets. Portable mobile power pack output capacity = mobile power capacity mobile power conversion efficiency phone charge conversion efficiency * adapter cable adapter efficiency General mobile power conversion efficiency is about 80%, can reach 85-88%, the ordinary phone charge conversion efficiency is about 75%, adapter cable adapter loss generally is 10%, then the adapter cable adapter conversion efficiency is 90%, then about 5200MAH mobile power finally be able to use phone only: 5200 * 0.85 * 0.75 * 0.9 = 2983.5mAh A look clear enough to iphone4 charging twice electricity. 5000mAh mobile power supply, if the conversion rate is not high, it can not be washed twice electricity.