18650 lithium battery as the density of the unit capacity is very big, so most of the used for laptop batteries, in addition, in 18650 at work stable performance is very good, the major are widely used in the electronics field: commonly used in high-grade light flashlight, portable power, wireless data transmission, electric thermal clothing, shoes and portable instruments and meters, portable lighting equipment, Portable printers, industrial instruments, medical instruments, etc.
So how to choose high-quality 18650 lithium ion battery? According to our electrical equipment to choose the most suitable for their own 18650 lithium battery, such as the appropriate brand, voltage, capacity, continuous discharge rate, battery life, etc., the most important is to choose a high safety battery. Below we will expand the detailed introduction one by one:
1, brand
About brands, there are sanyo, Samsung, SONY, LG and other international famous brands. Sanyo, LG main routine, the main application is strong light flashlight, charger, notebook batteries, etc. SONY professional, the main power current. Take VTC4 for example, discharge current up to 30A, electronic cigarettes, toys, etc., can easily competent.
2. Nominal capacity
The nominal capacity of 18650 battery is related to the endurance capacity, the unit is "mAh", the higher the capacity, the stronger the endurance capacity, for example, 2800mAh battery, with 1.4A current can continue to discharge for 2 hours.
3. Continuous discharge current (CDR)
Continuous discharge capacity is expressed by C number, continuous discharge current = continuous discharge capacity C number x capacity. For example, an 18650 battery has A capacity of 2800mAh and A continuous discharge capacity of 0.5C, so the continuous discharge current =1.4A. Discharging over 1.4A for A long time will seriously affect the battery life, and there may be overheating, even combustion, explosion and other risks.
5, internal resistance
Internal resistance is the resistance of the battery itself, the smaller the internal resistance is on behalf of its own consumption, the stronger the discharge capacity, the internal resistance this parameter will generally be written to the battery introduction page, when you choose and buy should also pay attention to look, try not to buy more than 100m ω more than the cell. Multiple 18650 series use must buy the same brand of the same type of battery, otherwise large internal resistance, low capacity of the battery will become a short board.
6, temperature,
Temperature is a major factor affecting the life of 18650 lithium battery. The higher the temperature, the faster the aging of the battery will be, and the higher the temperature, the greater the damage to the battery interior.
7. Pointy and flat heads
18650 lithium battery also has flat head and pointed head. The positive pole on the left is pointed, while the positive pole on the right is flat head. In general, I recommend buying pointed batteries to ensure they are compatible with a wide range of devices and uses. Usually the positive and negative poles of the flashlight are designed with springs, which can be retractable, and can be used by pointed and flat batteries. But if the flat battery is used in series, the positive end of the flat battery cannot touch the negative end of the other battery.
8. With and without protection plate
Tip 18650 with protection plate, flat head 18650 without protection plate. The 18650 lithium battery with protection plate is several mm higher than that without protection plate, and the price is slightly more expensive, but the safety is higher and the versatility is stronger. The 18650 lithium battery with protection plate can prevent the over-release of the battery, which will cause the lithium battery to heat, even combustion, explosion and other dangers.
Of all the 18,650 lithium-ion batteries, LiSOCl2 has the highest energy density and can last up to 15 to 20 years. The battery is especially suitable for devices with low and relatively short power supply currents. Due to the long battery life, low self-discharge rate, battery environmental resistance is also very good.
