Definition of the difference between power batteries and capacity batteries:
1. Capacity batteries can discharge at a maximum 3C current;
2. Power batteries generally refer to batteries that can discharge at a current of 5C, and ultra-high rate power batteries can discharge at a current of 20C or higher.
Capacity batteries are mainly designed to provide products with longer battery life, with energy density as the main research and development direction for lithium batteries. With the improvement of technology, the battery capacity and endurance are gradually improving, and the volume is also constantly decreasing. The application areas include consumer electronic devices, mobile phone batteries, power banks, and so on.
Power batteries are mainly designed to provide products with high discharge rates and continuous stable voltage and current, with battery safety as the basic principle and improving the reliability of product operation as the main research and development direction of lithium batteries. Simply put, power batteries are a type of power source that provides power for tools. Power batteries require advanced process control, consistency control, and quality management. The application areas include automotive electronics, avionics, drone batteries, starter power, igniters, and so on.
What are the differences between capacity batteries and power batteries? Let's continue reading. Many people are concerned about the difference between power batteries and consumer grade batteries. We believe that from the perspective of batteries, there is no essential difference. However, due to the different application conditions of the products, the design concepts and ideas are also different, which leads to significant differences in the product attributes of batteries in different fields that we see.
1、 Different discharge
1. The internal resistance of a capacity battery is high, and the discharge current per unit time is small. The power battery has a low internal resistance and a relatively high discharge current per unit time due to the high power of the equipment it needs to drive.
2. The power battery adopts double stacked bipolar ears on a single unit basis, or is connected in parallel with multiple units to increase the current of the entire battery pack. The battery capacity is affected by the output current, so the direct effect of parallel connection is to increase the capacity of the power lithium battery pack. And the capacity of the battery pack connected in this way is often relatively large, due to the large internal resistance and small discharge current, so the continuous discharge time is longer.
2、 Different voltage levels
Power type lithium battery packs can meet the needs of some high-power devices; The output voltage corresponding to a high voltage will also increase; The capacity type lithium battery pack adopts a parallel connection method to directly increase the current of the entire battery pack, and the capacity is affected by the output current, so the parallel connection directly increases the capacity of the lithium battery pack;
3、 Different volumes
1. Capacity batteries are mostly used in consumer products and are generally smaller in size, such as smartphones, power banks, etc.
2. Power batteries provide power and are generally larger in size, such as drone batteries.
4、 Different products applied
On some large devices, high voltage values are required, and low-power battery packs cannot operate, so it is necessary to choose power type lithium battery packs. For example, the voltage required for the electric bicycle we usually use is often 48V. Compared to some situations in our daily life, 48V is already quite large. So it is necessary to use power type lithium battery packs to ensure the operation of electric bicycles. And we usually go to some large supermarkets or shopping malls, some sign lights, and backup power supplies. Because the power consumption of these devices is not very high, they usually use capacity type lithium battery packs, which are different in product applications.
5、 Different internal resistance
The internal resistance of power lithium-ion batteries is smaller than that of capacity lithium-ion batteries. Taking 18650 as an example, 3-rate discharge generally comes with PDC, with an internal resistance of about 40; 5-rate discharge generally does not come with PDC, with an internal resistance of around 20.
6、 Different cycle life
Capacity batteries are generally consumer electronics products, and due to rapid updates and mild discharge environments, the design does not focus on cycle life. The usage environment of power batteries is relatively harsh, and the product has a long service life. Therefore, when designing, the cycle life is considered. Although in actual use, it feels that the cycle life of power batteries is very short, most of them are between 300-500 times. However, with a daily charge, mobile phones have been used for several years and even thousands of times. Some people say that the cycle life of capacity batteries cannot match that of power batteries, which is incorrect; In the same environment, the cycle life of power batteries is much longer than that of capacity batteries. If capacity batteries are used instead of power batteries, under other unchanged conditions, they may only be used dozens of times.
7、 Security issues
1. Self safety: Capacity batteries are generally used alone, while power batteries are usually used in groups, making the safety design of power batteries more complex. In terms of heat dissipation, capacity batteries can completely dissipate heat through themselves, and when designing heat dissipation for power batteries in groups, heat dissipation channels should also be considered.
2. Product safety: Capacity batteries do not have high requirements for product protection, and most of them are designed for the safety of the product itself. Therefore, capacity batteries only rely on the material and design of the battery to resist various safety hazards on the basis of higher energy density. The product body of power batteries generally has higher value, more design redundancy, and the use of better separators, foils, and casings, as well as more external protective circuits, heat dissipation layouts, etc., to ensure the safety of the product body. Of course, it can also be used in more adverse conditions (higher external voltage, larger current, and more complex external environment). So, different environments require different types of lithium batteries, and ultimately achieving one's own needs is the best!