For outdoor work, especially friends in the self-media industry, power bank must be a must-have, but have you chosen the right qualified power bank?
Now go to any brand to search for power bank, there are all kinds of power bank, you are dazzled, and you, how to choose the qualified one from the uneven power bank?
In fact, we may have been fooled by these manufacturers for many years, you pay attention to those small and exquisite, but the battery capacity is amazingly large power bank, I can say responsibly, it must be the kind of pit you did not negotiate manufacturers.
Let's first take a look at a few key parameters that reflect the quality of the power bank.
1. Milliampere-hour (mAh)
This is one of the parameters that every manufacturer likes to hype up in the title, and most users will mistakenly think that this is the standard for measuring battery capacity, and mistakenly believe that the larger the data of milliampere-hours, the stronger the battery life, which is the easiest entry point for manufacturers to fool Xiaobai.
Amperes (A) is the unit of electric current (I), which indicates the speed at which charges flow, milliamperes (mA) is the smallest unit of measurement in amps, 1A = 1000mA, and milliampere-hours (mAh) is the number of charges passing through the conductor per hour.
In other words, how can milliampere-hours (mAh) measure the true capacity of a battery? It also requires a key parameter, which is voltage (U).
Second, the energy of the battery
The capacity and energy of a battery are different concepts, with capacity representing the amount of charge that a battery is capable of storing, and energy representing how much power the battery is capable of providing.
1. Power(W)
We know that power (W) = voltage (U) × current (I), then, the power of a battery is the working voltage × current, and the current here is the identified milliampere-hour (mAh).
2. Energy watt-hour (Wh)
Watt-hour (Wh) is the maximum power provided per hour, which is what we call energy, which is the standard for measuring the capacity of a power bank.
Watt-hour (Wh) = Ampere-hour (Ah) × voltage (V).
3. Common pitfalls of power banks
1. The capacity is falsely marked
The following is an unknown brand of power bank, claiming 66W fast charging, 50,000 mAh capacity, but the price is more than 100 yuan.
From its labeling, it can be seen that the output energy is 74Wh, so let's first take a look at its true capacity, according to the formula, energy (Wh) = 50Ah×3.7V, the calculation result is 185 watt-hours (Wh), and why is it marked 74 watt-hours, less than half?
According to the formula, let's calculate it in reverse, what is the correct capacity of the marked 74 watt-hours, current (Ah) = watt-hours÷ voltage = 74÷ 3.7 = 20Ah = 20000mAh, which is twice as bad as this label.
2. Charging power
Many power banks are marked with fast charging, and the power is marked to the maximum as much as possible, however, the power marked does not indicate which output interface it is, by the way, this is the second pit of the power bank.
In order to fool consumers, many unscrupulous merchants make a big fuss here, taking the sum of the output power of all output interfaces as the selling point of publicity, what does it mean? For example, the advertised is 120W charging power, the power bank has a total of 3 output interfaces, two USB, one type_c, in fact, 120W is the sum of the power of the three interfaces, not the output power of a single output interface.
3. Super fast charging
Today's mobile phones support all kinds of fast charging, flash charging, and charging treasure also have to keep pace with the times, so, whether it can achieve fast charging or not, it doesn't depend on how he publicizes, we have to see whether it supports the PD protocol.
The choice is also very simple, directly look at whether the parameters indicate that it supports the PD fast charging protocol, and skip it directly if it is not marked.
IV. Conclusions
1. Milliampere-hours (mAh) is not a standard for measuring the capacity of the power bank, it must be calculated with the above formula to see what the real energy is and whether the parameters are false;
2. The output power must be paid attention to, and it is necessary to buy a power bank with power labeling for each interface;
3. You must choose a power bank that supports the PD protocol;
4. Don't buy unknown brands, especially the kind of power bank with super large capacity and small size, you definitely can't buy it.
【Conclusion】The parameters of the power bank are the standard for measuring its quality, but you must understand what the various parameters mean, otherwise you can't understand it, the manufacturer does not fool you, and who fools?