Choose any product, it should be said that the one that suits you is the best. Regarding the selection of lithium batteries and even battery products, the following aspects are generally considered:

1. According to actual use

Large-scale energy storage: Generally, comprehensive factors such as environmental protection, service life, and floor space are involved. Generally, it is recommended to use lithium iron phosphate battery cells, especially large-capacity lithium iron phosphate batteries;

Small energy storage: generally you can choose 26650, 32650 lithium iron phosphate battery cells;

Small power: Generally, you can choose the same battery as the small energy storage, or you can choose a relatively safe ternary material system battery; you can take into account the volume ratio energy and weight ratio energy issues;

Portable products: generally use 18650 ternary system batteries; polymer lithium cobalt oxide system batteries can be considered for higher energy requirements.

Smart wearable products: Generally, it is better to use batteries with the same size and small internal resistance, which can better exert the design capacity and meet the requirements of use.

Special battery: Need battery expert advice, which one is more reasonable.

2. Discharge rate

Ordinary products use products with a general magnification rate of no more than 0.5C, and use ordinary formula lithium batteries.

If the product is used for more than 1C, generally the life of the product and the use environment should be considered; especially for the charging environment, the charging current of lithium batteries generally needs to be derated under high and low temperature conditions, that is, batteries that should be charged less than 1C. In the low temperature state, the charging current is generally less than 0.2C to be ideal.

Lithium batteries with a discharge exceeding 2C are called rate-type batteries; generally, special formulas are required to meet the usage requirements. If ordinary batteries are used, it will lead to poor life and safety hazards.

Generally speaking, batteries with a magnification rate of more than 5C do not have a long service life, generally no more than 100 cycles. With the further development of technology, subsequent products may increase the product life, but other technical indicators are generally sacrificed at the same time. Model airplanes, unmanned aerial vehicles, and batteries in special fields have high-rate requirements. A battery with a relatively short instantaneous discharge time is not considered a high-rate battery.

3. Temperature environment

Batteries are used according to different temperature environments, and are divided into three categories: high-temperature batteries, low-temperature batteries, and conventional batteries; general high-temperature batteries refer to storage at high temperatures and generally do not discharge. If there is a discharge requirement, The product should not exceed 65 degrees or 70 degrees. Generally, high-temperature charging will also exist when discharging in high-temperature environments. For example, a dash cam battery is not only discharging at high temperature. Generally, designers do not understand the battery and do not limit high-temperature charging. At this time, the destructive effects of high-temperature charging on the battery are the deadliest. It also caused the bulging of such batteries and even other undesirable conditions. If the motherboard can be designed for high temperature protection, it can bring benign conditions for the lithium battery. Generally, it is recommended to set the high temperature discharge protection at 70 degrees; the high temperature charge protection at 55 degrees is more appropriate, although the lithium battery is charged at 0~ 45 degrees, but in the range of 45 to 55 degrees, if you charge with a small current, there is no big problem, and it is generally considered safe.

4. Use the lower limit voltage of the platform

generally refers to the lower limit voltage of an electrical appliance. When we select a battery, we fully consider the voltage range of the electrical appliance so that the lithium battery can be fully used. Therefore, when choosing a lithium battery, you must first understand which voltage range your product should use, and choose a lithium battery with the correct voltage range to make the entire product design more reasonable.

5. Cooperate with charging system

The charging management system for lithium batteries is very important. A strict constant current and constant voltage charging mode must be installed. If charging is performed beyond this mode, the product will not get a good charging effect, which will eventually affect the service life, and it may be serious. Lead to safety issues. Generally, the design of lithium batteries is safe, and improper use and charging are high-prone areas for lithium battery safety problems.

6. Is the battery with high specific energy necessarily good?

It is better to choose high specific energy batteries, and it is better to use them in batches after the actual test life; high specific energy batteries must be verified before they can be put into use. Any product needs this process. Generally, the high specific energy battery designed by the battery manufacturer will sacrifice other performance. No product is perfect. If the sacrificed battery short board is just what you need, then you can’t consider the original design. Need to redesign and revalidate.

7. The similarities and differences between energy storage batteries, rate batteries, and conventional batteries

Generally speaking, UPS energy storage batteries must take into account the rate performance; most UPSs are temporarily used as a temporary alternative to the mains for 5~10 minutes. That is to say, the battery generally needs to be discharged at a rate of 5~10C to meet the requirements. We must remember Don't think that you don't usually use batteries and you should take care of designing products.

Large-scale energy storage generally does not require rate-type batteries.

Rate batteries are generally common in model airplanes, drones, and video game products. But generally do not expect to have a long service life.