1.What Is Battery Capacity
Battery capacity is one of the important performance indicators to measure battery performance. It represents the amount of electricity released by the battery under certain conditions (discharge rate, temperature, termination voltage, etc.) (JS-150D can be used for discharge test), that is, the battery capacity, usually based on The unit is ampere·hour (abbreviated as A·H, 1A·h=3600C).
The battery capacity is divided into actual capacity, theoretical capacity and rated capacity according to different conditions. The battery capacity C is the integral of the current I from t0 to t1, and the battery is divided into positive and negative poles.
2. Classification of battery capacity
The battery capacity is divided into actual capacity, theoretical capacity and rated capacity according to different conditions.
The minimum capacity provided for discharging at a certain discharge rate at 25°C to the final voltage is the battery capacity specified during design and production, which is called the rated capacity of a certain discharge rate RH.
The battery capacity is generally calculated by AH (ampere hour), and the other is calculated by CELL (unit plate) several watts (W). (W/CELL)
1.Ah (ampere hour) calculation, discharge current (constant current) I × discharge time (hour) T. For example, if a 7AH battery has a continuous discharge current of 0.35A, the time can be continuous for 20 hours.
2. The charging time is 15 hours as the standard, and the charging current is 1/10 of the battery capacity. Fast charging will shorten the battery life.
The battery capacity refers to the amount of power stored in the battery. The unit of battery capacity is "mAh", and the Chinese name is milliampere-hour (when measuring large-capacity batteries such as lead storage batteries, for convenience, it is generally represented by "Ah", and the Chinese name is Ah, 1Ah=1000mAh). If the rated capacity of the battery is 1300mAh, that is, the current of 130mA discharges the battery, then the battery can continue to work for 10 hours (1300mAh/130mA=10h); if the discharge current is 1300mA, the power supply time is only about 1 hour (actual working time There are some differences due to individual differences in the actual capacity of the battery). This is an analysis in an ideal state. The current when digital equipment is actually working cannot always be constant at a certain value. Change), so the battery can only provide an approximate value for the power supply time of a certain device, and this value can only be estimated through actual operating experience
3. Battery capacity unit
Usually we say that the battery capacity is based on ampere-hour, which is based on a certain battery that has been determined.
For example, what is the battery capacity of this mobile phone; what is the battery capacity of this battery car,
They are all for different batteries. Regarding the battery voltage has been determined, without considering the actual voltage, only the ampere hour can represent the battery capacity.
However, for batteries with different voltages, we cannot simply use amp-hours to represent capacity. For example, a 12V 20AH battery or a 15V20AH battery, even if they are both 20AH, can supply the same power load, and the device can work normally, but the duration It is not the same, so the standard capacity should be based on work.
For another example, a device can support 12V and 24V. It can be powered by a 12V (20AH) battery and can provide one hour. Then using two pieces in series will become 24V (20AH). The ampere-hour does not increase, but it continues The time will be doubled, so the capacity should be considered as the work contained in the battery at this time, rather than simply as ampere-hours.
W (work) = P (power) * T (time) = I (current) * U (voltage) * T (time)
This discussion of battery capacity is of practical significance, and it must be realistic, otherwise there may be a claim that a mobile phone battery has a larger capacity than a battery car battery, which is obviously unscientific.