'Equivalent substitution' Learning mathematics in junior high school, the words most heard in physics, the need to achieve equal substitution is necessary, if there is not enough condition, even the same amount may not be able to substitute.
Taking a battery as an example, we know that the battery has several important parameters, which are operating voltage (V), milliampere-hour (mAh), and our common watt-hour (Wh) on laptop battery. We are comparing battery capacity. The size of the time will be compared with the mAh (mAh), such as Nanfu battery, mobile phone battery and rechargeable battery.
It is generally believed that the larger the mAh, the longer the battery life will be. However, the capacity of these batteries cannot be compared simply by the milliampere time. Take Huawei's mobile phone and Huawei notebook batteries as an example:
Huawei Huawei Mate book X notebook
↑↑↑ Huawei mobile phone battery capacity 3000mAh
If the battery life is calculated in milliampere hours, the endurance of two Huawei mobile phones is equivalent to the lifespan of a Huawei laptop. This is obviously unrealistic. To understand the impact of the battery on battery life, in addition to understanding the voltage, To understand the relationship between watts and milliamps.
Impact on battery life is not the only factor
So what exactly does Watt-hour (Wh) have with mAh? Let's review the definition of current in physics: Q=It can be known from I=Q/t, if the unit of current I is mA (milliampere), t represents time, unit hour, mAh represents the amount of charge in the battery.
That is to say, if a battery capacity identifies 1000mAh, the current can be used for 5 hours in theory when the current is 200mA.
But the formula Q = It does not involve the voltage, so milliampere hour can only explain how much charge the battery can hold inside, and can not explain how much power the battery can do, and what the maximum power the battery can provide.
In the above, we also mentioned that the operating voltages of different batteries may be different, so there will be a number in Watts (Wh) next to mAh on some batteries.
Recall from the definition of physics formula: W=UIt=UQ, the unit of voltage U multiplied by current I is W (Watts), so how much work can be done is represented by Wh (Watt Hour).
For example, this figure shows the MagicBook's built-in battery: 56.3Wh=7.6*7410mAh/1000, so we can calculate the operating voltage and milliamperes times on the battery without watt-hours.
For example, in the above figure, the capacity of 3500mAh battery, according to our customary comparison method, its capacity is half of the Huawei notebook.
But through the conversion found: 3.85V*3500mAh/1000=13.475Wh (approximately equal to 13.48), so even if the surface seems to be two Meizu 15 mobile phone battery can be top glorified Magic book battery, but in fact the battery capacity is still There is a lot of difference, and the endurance level cannot be compared.
In the same voltage situation, it is feasible to use milliampere hours (mAh) to compare the capacity of the same kind of battery, but if it is to compare two different products of the battery, their operating voltage is not the same, you must use watt-hours (Wh) for unit comparison.
If there is no watt hour (Wh) mark on the battery, the operating voltage (V) can be multiplied by milliamp hours (mAh) and then divided by 1000 to convert Wh.
Maintaining batteries can delay battery aging
When we work, we can use a computer to record some data files; when we study, we can use computers to check out some of the questions we don't understand in our studies.
Laptops are now surpassing desktops in sales on the market, but many people may find that their laptops are not as durable as they used to.
In the process of use, it is not necessary to deliberately charge the battery to 100%, or to use the computer without power will automatically shut down the computer.
The correct maintenance method should be to use the computer's power to about 20% to start charging. When the power is charged to about 98%, you should stop charging.
When using some external power supply, we do not need to remove the battery. Because of the protection circuit in the computer, the battery will not be overcharged even if it is not used in the notebook.
Normally, the life of a laptop battery is between 300 and 500 charge and discharge times. It is best to charge the computer at any time to reduce the number of charge and discharge times of the battery as much as possible so that the battery can be reduced as much as possible. Life loss.
General batteries are very sensitive to temperature. Whether the environment is too hot or too cold is not good for batteries. Overheated environment will accelerate the passivation reaction of the battery itself. Undercooled environment will destroy the internal structure of the battery. The battery is stored at a suitable temperature.
