recently many online users are asking: mobile power I 5000mAh how to iPhone4 charge two times can not ah!
With iPhone4 friends all know lithium battery 1420 milliamperes, logically speaking mobile power supply for 5000mAh can iPhone4 charging 3.5 times ah! Two how can not ah! In fact, such a calculation is wrong, because the mobile power supply with mobile phones have a loss of
Many friends don't know mobile power supply conversion rate is how to calculate the.
Principles of mobile power supply is the battery voltage to the standard 3.7 - 4.2V, the boost to 5V, and can charge the mobile phone, mobile phone itself also has a charging circuit, the two will have a loss.
Mobile power supply capacity that we say normally refers to the capacity of the electric core. Process to charge a mobile phone in the mobile power supply, circuit board mobile power itself will loss of electrical, adapter is in power, at the same time the mobile phone itself in power consumption!
The conversion of mobile power supply and usually said the rate = (the actual discharge capacity * average discharge voltage) / (the actual core capacity * voltage). Because the standard mobile phone battery voltage is 3.7V, the standard voltage of the mobile power supply electric core for 3.7V. Many people will see this voltage to ignore! It is necessary to consider the electric core voltage when computing the notebook. The battery voltage is 14.8V, ranging from 19V notebook.
Here's the real discharge magnitude is said the release of electricity, not the final mobile phone access to electricity.
Mobile power supply actual output capacity = mobile power capacity * mobile power conversion efficiency * mobile phone charging conversion efficiency * transfer line adapter efficiency of
General mobile power conversion efficiency is about 80%, better can reach 85-88%, the ordinary mobile phone charging conversion efficiency is about 75%, the loss of transit line adapter is generally is 10%, then the transfer line adapter for efficiency is 90%, then the 5200MAH around mobile power supply, to finally be the phone completely use only: 5200*0.85*0.75*0.9=2983.5mAh
Such a view is clear, sufficient can give iPhone4 two electric charge.
5000mAh mobile power supply, if the conversion rate is not high, cannot rushed two times of power