When it comes to mobile power, everyone is very familiar. His size is fat and thin, the design is playful and cute, and he is calm and restrained. The biggest use is to provide power for digital products. It is convenient to carry around. Just like everyone has a mobile phone, mobile power has become an indispensable part of people's lives. An item.

I. Introduction
In most people's eyes, mobile power is just enough for them to charge, but mobile power varies widely, performance parameter capacity is different, choose the right product, can bring a better experience. For a mobile power supply, there are several important parameters that are important: power, capacity, and protocol. The high power can support faster charging and discharging speed, the capacity can provide longer battery life, and the protocol compatibility can better match the device to increase the charging speed. Today, Xiaobian starts with the parameter of “capacity”.
At present, the common mobile power supply capacity on the market is 10000mAh, 20000mAh, and 30000mAh. Of course, some brands have introduced mobile power supplies with a capacity of less than 5000mAh and even a single 18650 battery capacity of only two or three thousand milliamperes. The power supply is good, but is everyone suitable?
Maybe not necessarily. Large-capacity mobile power supplies can provide longer battery life, but the weight is relatively larger. The experience of using too heavy mobile power will be greatly reduced. The mobile power with small capacity is relatively small. Carrying a great experience, but the endurance is not as strong as the bulk. So how much mobile power should we fit in for us? Today, Xiaobian will talk with everyone about "How much mobile power is suitable for us?"
Second, how much energy is needed to fill a device
First we need to figure out how much power is needed to fully charge a device, and how much power a mobile power can charge it. Some people say that this is not simple. A mobile phone with a battery capacity of 3300mAh will definitely consume 3300mAh. If it is charged by a mobile power supply of 10000mAh, 10000 divided by 3300 can be filled at least three times.
This is not true because the power transfer between them is boosted from the battery core to the USB output, the cable is transmitted, and the mobile phone is stepped down to the mobile phone battery. There is efficiency conversion between the buck-boost and the voltage drop. The factor of (loss) exists. In addition, the voltage of the discharge platform of each device is different. It cannot be calculated directly by the unit of charge quantity, that is, mAh. Here we need to convert it into energy: Wh.
The conversion formula is: Wh = mAh / 1000 × voltage.
The voltage refers to the cell voltage of the mobile power source or the battery voltage of the digital device such as a mobile phone (discharge platform). Generally speaking, the voltage of the mobile power battery is 3.6V, 3.7V, 3.85V. Here we take 3.7V as an example, and the voltage of the mobile phone battery is mostly 3.85V. Suppose a mobile power supply has a capacity of 10000 mAh, then its energy is 10000/1000*3.7=37Wh; if the battery capacity of the mobile phone is 3300 mAh, then its battery energy is 3300/1000*3.85=12.7Wh.
Knowing the energy level can easily calculate how many times this mobile power can charge the phone, here we have to use another formula: charging times = mobile power / mobile phone battery energy * conversion efficiency.
Generally speaking, when the mobile power source charges the mobile phone, the conversion efficiency of the overall loss is about 70%. We bring the energy and efficiency directly into the formula, 37Wh/12.7Wh*0.7≈2.03, and learn a 10000mAh. The mobile power of the capacity can fully charge the 3300mAh mobile phone about 2 times.
Third, how much mobile power is suitable for yourself
1, first ask yourself what is the main equipment charging
Mobile phones, tablets, notebooks, cameras, game consoles... There are so many products that need to use mobile power, but mobile phones charge different life for each device, just like mobile phones, mobile phones are generally Around 3300mAh, a 10000mAh mobile power supply can charge it twice. If it is a laptop, it will be different.
Take the Xiaomi notebook Air 13.3 inch as an example, he supports the latest 20V USB PD fast charge input, the battery energy is 40Wh, if you charge it with 10000mAh mobile power, then the mobile power can charge it 37Wh/40Wh*0.7≈0.64 times In addition, the charging power of the notebook is higher, and the boost voltage difference of the mobile power supply will be lower. The actual conversion rate may not reach 70%. The final result is that the mobile power of 10000mAh may still be less than half of the power of the notebook. . Therefore, there is no 20000mAh mobile power supply to charge the notebook. It is also necessary to pay attention to when choosing a mobile power supply for the notebook to see if it supports the same fast charge protocol, and the size of the power, the power is better than 45W. .
For small devices like mobile phones and cameras (micro-single), you just have to think about how much power you need to charge it continuously, and products like energy and power consumption like laptops. How to meet 20000mAh+, and there are many requirements in the charging protocol and power.
2. How many devices do you need to guarantee battery life?
As mentioned above, mobile phones, tablets, notebooks, cameras, game consoles... there are so many products that need to use mobile power. Some small partners need to charge the mobile phone and charge the tablet, which requires a large-capacity mobile power supply. Let's take a 3300mAh battery-capable mobile phone and an iPad Pro 11-inch (battery capacity 29.37Wh). If you need to charge each time, you need at least one (29.37+12.7)/0.7≈60.1Wh. About 16243mAh capacity of mobile power, according to the market mobile power capacity classification, 20000mAh did not have to run. If there are not many devices, the capacity can be slightly smaller to reduce the cost of carrying, and vice versa.
3. What kind of habit is usually used?
There are no two identical products in the world. The habits of people are the same. Everyone has different habits and the habit of using a product. How do you get used to using mobile power? Is it more like to be in the hand or in the bag? Do you prefer to use it at home or outdoors?
The larger the capacity of the mobile power supply, the larger its volume will be. This should be very clear to everyone. This will also be a good understanding of why the choice of mobile power capacity will be related to usage habits. If you are used to going out with one hand and holding a mobile phone with mobile power, you must not choose a larger or thicker mobile power supply, so it is impossible to choose a style with too much capacity; if you prefer to be at home Use the mobile power supply without the restraint of the socket. The size factor of the mobile power supply should not affect your experience too much. It is not bad to choose a mobile power with a large capacity.
Most mobile power supplies with a capacity of 10000mAh and below are relatively thin and light, and there is no big problem with one-handed holding of the mobile phone; the mobile power supply of 20000mAh is relatively large, and it is difficult to hold the mobile phone with one hand. More than 20,000 mAh capacity, not to mention, if you want to hold the phone with one hand at the same time, then you may need a pair of Yao Ming's hand, or for these large capacity, you can only use the mobile power in the backpack. .
4. Is it used by many people with high load?
I think that most people's mobile power is mainly used as a home, such as a friend to go out together. If you just go out and find friends to gather for a meal or something, do not do any high-power operation (such as games), 10000mAh or even lower mobile power can meet your needs, small size can be easily into the trouser pocket, carry It is very convenient; and if it is about a group of friends who open black "eat chicken", the capacity requirement for mobile power is naturally higher.
About a friend to the cafe to open black for five hours, according to Xiaobian personal experience, the phone needs two full power state to play happily, plus the friend's mobile phone also needs to charge twice, taking the mobile phone battery capacity of 3300mAh as an example. Then you need to bring a mobile power supply of at least 20,000mAh to go out, or else you can't blame for bad luck if you don't have a power out of the middle.
5, figure out the use time to take out
Many office workers can't help but go out to do business or go out of business. Is it a short time to go out and do something, or is it a long-term business trip? This factor is also related to the size of the mobile power source.
If you want to go out for a short time, you don't need to carry a mobile power with too much capacity, so as not to increase your own burden. If you are going on a business trip, traveling, etc. for a long time, try to choose a large-capacity mobile power supply. Preparation is the king.
6. What kind of people do you belong to?
The last point is which type of people belong to them, such as the student party (high school students)? Office workers? Or boys or girls?
For boys and girls, it is very understandable. The capacity and weight are relatively high. In the traditional sense, the mobile power with too high weight will bring more stress to girls than the boys, and the experience will be even greater. Influence, some lightweight "Kawaii" designs often become standard for girls.
For the student party (high school students), it is always difficult to find a socket that can charge mobile phones and other equipment, especially for students. There may be sockets in the classroom, but when is the whole class waiting so far? At this time, an ultra-large mobile power supply is necessary.
7, mobile power supply durability
One of the factors that affects the durability of mobile power supplies is the size of the capacity. Larger capacity than the smaller capacity will be more durable, which is related to their charge and discharge "magnification". When the same device is charged at the same power, the smaller the capacity of the mobile power source with smaller capacity, the smaller the loss. If you are a heavy user of mobile power, the small-capacity mobile power will lose half of it in a few months, and the mobile power loss of 20000mAh and 30000mAh will be much slower.
8, whether you want to carry mobile power to take the plane
In 2014, the "Announcement on the Regulations for Passengers Carrying "Charging Po" in Civil Aviation Passengers" issued by the Civil Aviation Administration of China has detailed regulations on personal portable charging boarding machines. The rated energy is not more than 100Wh and can be directly boarded. 100Wh-160Wh It is necessary to submit an approval to the airline in advance and obtain approval before boarding.
Rated energy 100Wh, about how much battery capacity? Because different battery voltages are calculated differently, Xiaobian lists several common voltages: single-string battery discharge platform 3.60V, which is equivalent to 27777mAh; single-string battery discharge platform 3.70V, which is equal to 27027mAh; single string power The core discharge platform is 3.85V, which is approximately equal to 25974mAh.
Third, the charging head network summary
The capacity of the mobile power supply is destined to affect our experience. The capacity is small and the voyage is convenient but easy to carry. The capacity is large and the battery life is good but the carrying cost is high. Is it a large capacity or is it convenient to carry? This requires you to choose according to the actual situation.
Used to charge the mobile phone, the capacity does not need to be too large, 10000mAh can basically meet two charges, used to charge iPad Pro, laptop, the capacity must be enough, at least 20,000mAh, and the laptop also has charging protocol and power for mobile power. There are certain requirements, PD fast charge notebook, recommended 45W and above output power; in addition to the daily use habits, use purposes, usage should also be taken into account, short-term short-distance travel priority to portability, long-distance long-distance Travel priority is given to the endurance. It is also necessary to take into account the transportation that the trip will take. For example, it is best to carry a mobile power supply of no more than 100Wh when flying. Of course, there are some specific use scenarios and other factors to be considered. intend.
PS. This issue is mainly introduced from the perspective of the capacity of mobile power. I share some thoughts on the selection of mobile power capacity. In the next issue, we will share another part of this series of topics - "Power". Welcome everyone to continue. attention.