Efficiency of banks and gadgets charge schemes
Power Bank (external battery, portable charger, power bank) - a box with batteries and electronics inside, allowing you to charge gadgets where there are no outlets.
Manufacturers of banks will never indicate the actual amount of energy that can give out power bank. Only the capacity of internal batteries in milliampere-hours is always indicated. Many people naively think that a power bank that says 10,000 mAh can charge a smartphone with a 2500 mAh battery four times. In fact, this is not the case.
I measured the amount of energy that five different banks worked and the amount of energy that five different smartphones and tablets took to fully charge the battery.
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The banks were discharged with a current of 950 mA.
According to the measurement results, the efficiency of the banks ranged from 78.7 to 94.3%.
It should be noted that I had the opportunity to measure the capacity of the internal battery only in the case of Miller, in the remaining four cases it remains only to believe (or not to believe) to the manufacturer. I can assume that the battery capacity in Just Mobile is actually less than the claimed 6000 mAh.
I also note that Xiaomi on the case indicates the battery capacity of 37.44Wh, calculated on the basis of the rated voltage of 3.6V (usually the capacity is calculated on the basis of the voltage of 3.7V).
Now let's see how much energy smartphones and tablets need to fully charge the battery. Before the experiment, the device battery was completely discharged, then charging was connected, and after a minute the device was turned on.
Charging devices require 29.2-43.1% more energy than their battery. For most devices, this excess is 37-38% and only the iPad has a more advanced charging circuit with high efficiency, giving an excess of 29.2%.
Thus, if you charge the most uneconomical in terms of charging, the smartphone HTC Desire Eye (battery 2400 mAh) from the Just Mobile PP-268 bank (6000 mAh battery), which has the lowest efficiency tested, the battery will last only 1.3 full charges, but not at 2.5 charges (6000/2400).
On average, we can assume that the efficiency of all electronics when charging a smartphone or tablet from the bank is about 65%.
Therefore, at approximate calculations, how many times this or that gadget will be charged from the bank, multiply the capacity of the batteries of the gadget by 1.5 and divide the capacity of the batteries of the bank by the resulting number.
Example: The smartphone has a 2000 mAh battery, in a crib - 6000mAh. 6000 / (2000x1.5) = 2. The test bank will be enough for exactly two charges.
ps Everything about ampere-hours, watt-hours and batteries in this article: habrahabr.ru/post/150661 .
© 2015, Alexey Nadyozhin.
Manufacturers of banks will never indicate the actual amount of energy that can give out power bank. Only the capacity of internal batteries in milliampere-hours is always indicated. Many people naively think that a power bank that says 10,000 mAh can charge a smartphone with a 2500 mAh battery four times. In fact, this is not the case.
I measured the amount of energy that five different banks worked and the amount of energy that five different smartphones and tablets took to fully charge the battery.
')
The banks were discharged with a current of 950 mA.
| Model | mAh | Wh battery | Wh on exit | Efficiency |
| Miller ML-102 V7.1 | 2580 | 9.55 | 8.46 | 88.6% |
| Huawei AP006 | 4800 | 17.80 | 16.79 | 94.3% |
| Just Mobile PP-268 | 6000 | 22.20 | 17.47 | 78.7% |
| Gigabyte OTG G66B1 | 6600 | 24.42 | 21,69 | 88.8% |
| Xiaomi NDY-02-AD | 10400 | 37.44 | 34.58 | 92.4% |
According to the measurement results, the efficiency of the banks ranged from 78.7 to 94.3%.
It should be noted that I had the opportunity to measure the capacity of the internal battery only in the case of Miller, in the remaining four cases it remains only to believe (or not to believe) to the manufacturer. I can assume that the battery capacity in Just Mobile is actually less than the claimed 6000 mAh.
I also note that Xiaomi on the case indicates the battery capacity of 37.44Wh, calculated on the basis of the rated voltage of 3.6V (usually the capacity is calculated on the basis of the voltage of 3.7V).
Now let's see how much energy smartphones and tablets need to fully charge the battery. Before the experiment, the device battery was completely discharged, then charging was connected, and after a minute the device was turned on.
| Model | mAh | Wh battery | Wh inlet | Excess |
| ASUS Zenfone 5 | 2110 | 7.81 | 10.73 | 37.4% |
| HTC Desire Eye | 2400 | 8.88 | 12.71 | 43.1% |
| Huawei Ascend P7 | 2500 | 9.25 | 12.57 | 35.9% |
| Samsung Galaxy Note 8.0 | 4600 | 17.02 | 23.54 | 38.3% |
| Apple iPad Air | 32.40 | 41.87 | 29.2% |
Charging devices require 29.2-43.1% more energy than their battery. For most devices, this excess is 37-38% and only the iPad has a more advanced charging circuit with high efficiency, giving an excess of 29.2%.
Thus, if you charge the most uneconomical in terms of charging, the smartphone HTC Desire Eye (battery 2400 mAh) from the Just Mobile PP-268 bank (6000 mAh battery), which has the lowest efficiency tested, the battery will last only 1.3 full charges, but not at 2.5 charges (6000/2400).
On average, we can assume that the efficiency of all electronics when charging a smartphone or tablet from the bank is about 65%.
Therefore, at approximate calculations, how many times this or that gadget will be charged from the bank, multiply the capacity of the batteries of the gadget by 1.5 and divide the capacity of the batteries of the bank by the resulting number.
Example: The smartphone has a 2000 mAh battery, in a crib - 6000mAh. 6000 / (2000x1.5) = 2. The test bank will be enough for exactly two charges.
ps Everything about ampere-hours, watt-hours and batteries in this article: habrahabr.ru/post/150661 .
© 2015, Alexey Nadyozhin.
Source: https://habr.com/ru/post/377145/
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