18650 Lithium-ion Battery

18650 battery definition

18650 battery is a common lithium battery model. Its name comes from the size of the battery, where "18" represents the battery diameter of 18mm, "65" represents the battery height of 65mm, and "0" represents the battery is cylindrical. This battery was originally invented by Panasonic Corporation of Japan and is now widely used in various portable electronic devices, such as flashlights, electric toys, portable electronic devices, and 18650 battery packs are used in some two-wheeled and three-wheeled electric vehicles.

Advantages and disadvantages of 18650 batteries:

Advantages:

1. High energy: 18650 batteries store more power in a smaller volume, providing longer use time for portable electronics.

2. High power: 18650 batteries are able to provide large currents in a short period of time, suitable for applications that require fast charging and high power output.

3. High safety: The built-in BMS (battery management system) of 18650 batteries adopts a variety of safety designs to prevent battery short circuits, overcharging, and over-discharging.

4. Long life: 18650 batteries usually have a long cycle life and can still maintain a high capacity after multiple charge and discharge cycles, which is crucial to extend the service life of the device.

5. Low self-discharge rate: This means that less power is lost during storage, which is conducive to maintaining the long-term storage performance of the battery.

6. Wide operating temperature range: 18650 cells operate in an environment of -20℃~+60℃, which makes them suitable for a variety of environmental conditions.

7. Standardized models: The size and interface of 18650 batteries are standardized, users can easily replace batteries, and there are many suppliers on the market with transparent prices.

Disadvantages:

1. Limited capacity of a single cell: The capacity of a single 18650 battery is usually between 2000mAh and 3500mAh. For devices that require more power, multiple batteries need to be used in series or parallel, which may increase the volume and weight.

2. Internal resistance increases over time: As the number of charge and discharge times increases, the internal resistance of the 18650 battery will gradually increase, resulting in weakened battery performance and reduced battery life.

3. There are safety risks: If the battery is mechanically damaged, overcharged, over-discharged or short-circuited, it may cause the battery to overheat or even catch fire, especially in uncertified battery products.

4. Correct charge and discharge management is required: In order to ensure the performance and safety of 18650 batteries, appropriate charge and discharge management circuits are required, which will increase equipment and complexity and cost.

5. Environmental treatment issues: 18650 batteries of different materials contain harmful substances, such as cobalt, manganese, nickel, etc., which need to be specially treated before they can be recycled, otherwise they will pollute the environment.