Lithium Battery Knowledge Introduction And Common | IMREN Battery

Lithium Battery Knowledge Introduction And Common | IMREN Battery

Lithium battery knowledge introduction
At the beginning, I will briefly introduce the basic knowledge of lithium battery. There are many types of lithium batteries in terms of package, material and shape. This article only introduces 18650, 21700 and other cylindrical lithium batteries commonly used in strong light flashlights

Meaning of lithium battery model
The lithium battery model represents the overall dimensions of the lithium battery. For example, the first two digits 18 of the 18650 lithium battery indicate that the diameter of the lithium battery is 18 mm. 65 means the battery length is 65 mm. 0 means the battery is cylindrical. The common lithium batteries used in flashlights are 18650, 21700 and 26650. In addition to these three common models, there are 26800, 18350, 26350, 14500, 16340 and other models. Try to buy lithium battery knowledge introduction and common 18650, 21700 and 26650 lithium battery evaluation flashlights using 21700 and 18650 lithium batteries. Other types of lithium batteries are also available. But few large manufacturers produce it. The quality is mixed

Voltage
The rated voltage of these lithium batteries is generally 3.7V. There are also a few 3.6V ones. The voltage can reach 4.2V when fully charged. The voltage will decrease continuously during discharge. It is completely dead until it is put at 2.5V. 2.8V is generally used as the discharge cut-off voltage. The voltage of cylindrical lithium battery for flashlight is generally universal. Don't pay attention to voltage parameters

Capacity
Capacity is one of the important indicators of lithium battery. The higher the capacity of the same type of lithium battery, the longer the battery life. IMREN has 18650 lithium batteries with the highest capacity. The capacity can reach 3500mAH (3600 but not available). Those higher than this value are imaginary; The maximum capacity of 21700 lithium battery can reach 5000mAH. 26650 At present, the maximum capacity of IMREN is 5000mAH.

Discharge current and rate
The discharge current and rate of lithium battery are also important indicators. It determines whether the battery is suitable for your flashlight. When purchasing batteries, first check whether the discharge capacity meets the requirements. Then consider the capacity. The discharge current is divided into continuous discharge and peak discharge. Continuous discharge means that the battery can discharge at this current for a long time under standard environment. The peak current is the current that the battery can withstand occasionally and instantaneously. Do not discharge at peak current for a long time.

Lithium battery knowledge introduction and common 18650, 21700, 26650 lithium battery evaluation, in addition to discharge current. Some battery parameter tables indicate the discharge rate. For example, 5C and 10C represent 5 times and 10 times. Discharge rate C number=battery capacity/1000. For example, 3000mAH lithium battery. 5C is equal to 5 * (3000/1000)=15A discharge current. 10C is 10 * (3000/1000)=30A discharge current. Many people like to use 18650 batteries from rechargeable batteries and laptops. This is not recommended. These batteries are generally capacity type. Lithium battery knowledge introduction and common 18650, 21700, 26650 lithium battery evaluation unless you can measure the discharge performance of these batteries yourself

About Internal Resistance
Internal resistance is the most important indicator of lithium battery. It determines the comprehensive performance of lithium battery. The internal resistance can be regarded as the resistance of the battery itself. It is connected in series with the drive board and lamp beads in the circuit. We all know that the formula of power is P=I ² R。 The higher the value of resistance R. The battery itself consumes more energy. This loss is consumed in the form of heat generated by the battery itself. To measure more accurate internal resistance value, we can only use internal resistance tester such as YR1030 to introduce lithium battery knowledge and evaluate common 18650, 21700 and 26650 lithium batteries. Or refer to the battery parameter table published by the manufacturer.

The lower the internal resistance of lithium battery. Represents lower loss. The stronger the discharge performance. For 18650 batteries. Lithium battery knowledge introduction and common 18650, 21700, 26650 lithium battery evaluation The internal resistance below 14 is generally high performance and high rate battery. The battery with tens of milliohm is usually a capacity battery. It's such a big size. Capacity and performance cannot be achieved at the same time. So you must first look at the discharge capacity when purchasing. If the battery with high internal resistance is used for large current discharge. From the formula P=I ² R can know that the power consumed by the battery itself has risen sharply. The battery will heat up quickly. The discharge performance of many batteries will be greatly affected by temperature. The service life is seriously affected. It may even be dangerous if it is discharged for a long time.

Many electric vehicles are actually composed of our columnar lithium batteries in parallel and then in series. No matter in series or in parallel, the capacity and internal resistance of each battery must be consistent before it can be grouped. If you are using lithium battery knowledge introduction and common 18650, 21700 and 26650 lithium battery evaluation, use a flashlight with multiple batteries. Whether in series or parallel. The same batch of batteries should also be selected (the internal resistance and capacity should be the same). Avoid individual batteries dragging the whole battery. Most of these lithium battery manufacturers do not do retail business.

With the introduction of lithium battery knowledge and the evaluation of 18650, 21700 and 26650 lithium batteries, it takes longer and longer to use and place. The internal resistance value will also increase. In addition. Voltage also affects internal resistance. For example, the internal resistance is different at 3.2V and 4.2V. The higher the voltage, the lower the internal resistance.

About Pointed and Flat Heads
When buying these columnar batteries, you should pay attention to the difference between pointed and flat ends. Pointed refers to the protruding anode of lithium battery. The first way to judge is to ask the merchant. The second is to unscrew the flashlight lamp and look at it. Generally speaking, if the positive pole of the flashlight is a spring. Then this flashlight can be used with pointed and flat batteries. Of course, a few flashlights only support flat-head batteries in order to slim down; If the positive pole of the flashlight is not a spring. Flat-head batteries may not make contact with the positive pole. This kind of flashlight can't use flat battery. There are also flat-head batteries, including the introduction of lithium batteries in series and the evaluation and use of common 18650, 21700 and 26650 lithium batteries. Some friends may want to buy a battery with a small magnet attached to the positive pole to change the flat end into a pointed end. Small power flashlights can do this. Introduction to lithium battery knowledge and common 18650, 21700 and 26650 lithium batteries will increase the internal resistance of magnets when measuring high power. Large impact

About storage and maintenance
Lithium battery storage has low environmental requirements. It is not recommended to use a storage box to put it in a cool and dry place for a long time. Take out the battery when the flashlight is not used for a long time. Most flashlights have a weak current consumption. If it is not used for a long time, the lithium battery knowledge introduction and the common 18650, 21700 and 26650 lithium battery evaluation may be finished. It affects the battery life. It should also be noted that if the lithium battery is stored for a long time, the voltage should be kept around the rated voltage. That is 3.7V

Remember that the discharge rate is the most important. Next is capacity! Consult the manufacturer to confirm how much current battery your flashlight needs. Don't buy blindly.

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