Capacity (mAh): rechargeable battery is mAh (mAh), is the product of current intensity and time, when the current intensity with a milliamp (mA) for the unit, the time in hours (h) to do unit, both of them Multiply that mAh (mAh). Which represents the discharge current in a full discharge time, for example, means 1000 mAh 1000 mAh The battery current may be discharged for 1 hour.
Mobile power capacity into not too strict distinction, the general mobile power capacity 1000mAh-12000mAh about considering mainstream smart phone 2000mAh battery capacity is generally about (such as millet M2 battery capacity of mAh, the battery capacity of the Samsung i9300 2100mAh), so we will move into 2000mAh power capacity by the following (one-time charge, considering the portability) ,2000-5000mAh (give phone charging 1-2 times), 5000mAh-10000mAh (give phone recharged many times, or to charge your tablet) and 10000mAh above (to charge multiple devices) four grades, and will be in the subsequent evaluation of these four grades of different models of mobile power for evaluation.
We also pointed out that for mobile power, the greater the capacity is not better, after all, the capacity can be measured using the time only one parameter. At the time of purchase, should be based on their actual usage habits and needs to choose, should not blind pursuit of "high capacity."
Also worth noting is that the mobile power capacity under normal circumstances is the manufacturer of the marked on the product packaging capacity value, this value is generally specific to mobile power capacity internal batteries capacity value, rather than many consumers think actual capacity value can be used.
Output Voltage (V): Imitation computer USB port and cell phone chargers, usually 5V;
Output Current (mA): Currently the more common output current standards 500mA, 1000mA (1A) and 2100mA (2.1A) and so on. The former two are generally used to charge the phone, which is common in larger capacity mobile power to charge your tablet. And capacity, the output current is also selected mobile power needs to be considered an important indicator. This is because, in the case of the same voltage, the nominal parameters of the device to be charged is more similar to the current of the charging process to allow more efficient. Output current of the equipment on the different charging efficiency, love machine will engage in subsequent tests to verify.
Input Voltage (V): Imitation computer USB port and cell phone chargers, usually 5V;
Input Current (mA): similar mobile power supply output current to directly affect the charging efficiency of digital products, mobile power input current will also directly affect the charging efficiency of the mobile power. For example, a 12000mAh mobile power, if the rated input current of only 500mA, which means that the time required for full mobile power up more than 20 hours; But if the rated input current of 2.1A, then only about seven hours or so, is the sleep time at night can be filled.
Conversion Rate (%): In layman's terms, mobile power mobile power conversion rate is the internal batteries for charging and discharging the conversion efficiency. For example, in theory, a 5000mAh mobile power, if the cross-flow 5V/1A power charging, then five hours can be filled, but in fact it is not. This is because both the internal telecommunications and mobile power protection board, power supply interface, the charging and discharging process will have some wear and tear, including:
Circuit switching losses;
Run their own loss;
Boost loss; like.
Which we feel is caused by loss of boost, "Why do not we move the power capacity of the imagination so big" reasons. Mobile power lithium batteries used in discharge voltage typically 3.7V-4.2V, while mobile phones and other digital products, standard input voltage of 5V, so mobile power needs through internal booster circuit, the output voltage of 5V to charge the phone , which were also a loss.
In simple terms, the so-called "capacity" only on behalf of the mobile power specified at nominal voltage output and current discharge capacity, but does not really represent the true energy of mobile power. When the battery's energy in watts (Wh) as a unit, as capacity (mAh) and the rated voltage (V) of the product, such as a 5000mAh mobile power, where the capacity of lithium batteries capacity, rated voltage of 3.7V, Therefore, the energy should be 5000mAh * 3.7V/1000 = 18.5Wh, but if after the boosted output to 5V, the output power is effectively 18.5Wh/5V * 1000 = 3700mAh, this is what we may be found in the use, a nominal 5000mAh mobile power, it may not give a 1440mAh for iPhone 5 full three times electrical reasons.
The conversion efficiency of the batteries directly determines the quality of mobile power. Generally, imported batteries discharge conversion rate is 85%, the domestic A product is about 75% -85%.
These are just to help users choose to move some of the key performance parameters of the power, but the mobile power markets varies greatly, virtual standard capacity, parameters such phenomena are endless, not only pay attention when buying parameters, reference should pay more attention to others experience.