18650 lithium ion battery cell

　　How to maintain UPS batteries and how to judge whether the batteries are good or bad?

　　If there is dust or surface contamination during maintenance of the 18650 lithium ion battery cell, it should be cleaned with water or a soaked cloth. Chemical fiber cloth cannot be used. In addition, the quality can be judged from the appearance and measured with a multimeter. Then the next step is Please introduce the relevant content in detail.

　　1. How to maintain UPS batteries

　　1. When storing, please be careful that the temperature does not fall below -20℃ and exceed the range of +40℃.

　　2. When storing the battery, the battery must be stored in a fully charged state. Since part of the capacity will be lost due to self-discharge during transportation or during storage, please replenish the battery at any time during use to avoid capacity reduction of the 18650 lithium ion battery cell due to long-term automatic discharge.

　　3. When storing for a long time, in order to make up for the self-discharge during storage, please perform supplementary charging.

　　4. Storage under conditions exceeding 40C will have a great impact on battery life. Please avoid it if possible.

　　5. Please store it in a dry, low-temperature, and well-ventilated place.

　　6. If the battery packaging is accidentally wetted by water during storage or transfer, the packaging carton should be removed immediately to prevent the wet carton from becoming a conductor and causing the battery to discharge or burn out the positive terminal (because water is conductive) .

　　7. Check the battery regularly. If dust or other external contamination is found, please clean it with a cloth soaked in water or warm water. Do not use organic solvents or oils such as gasoline and banana water for cleaning (to avoid corrosion to the 18650 lithium ion battery cell packaging structure), and please avoid using chemical fiber cloth.

　　8. During float charging, if the total voltage during battery charging or the indicator value of the voltmeter on the indicator plate deviates from the reference value shown in the table below (±0.05V/single cell), the cause should be investigated and dealt with.

　　2. How to judge the quality of UPS batteries

　　1. Judging from appearance

　　Observe the appearance for deformation, protrusions, leakage, cracks, explosions, burns, and oxide seepage at screw connections.

　　2. Load measurement

　　If there is no abnormality in the appearance, the UPS is operating in battery mode with a heavy load. If the discharge time is significantly shorter than the normal discharge time, the normal backup time cannot be restored after 8 hours of charging, and the battery is judged to be aging.

　　3. Measure with a multimeter:

　　a. Measurement in battery discharge mode: Measure the voltage of each battery terminal in the battery pack. If the voltage of one or more battery terminals is significantly higher or lower than the nominal voltage (nominal voltage 12V/cell), determine the battery aging.

　　b. Measurement in mains mode: the charging voltage of each battery terminal in the battery pack. If the charging voltage of one or more batteries is significantly higher or lower than other voltages, the battery is judged to be aging.

　　c. Measure the total voltage of the battery pack: The total voltage of the battery pack is significantly lower than the nominal value. It cannot return to the normal value after 8 hours of charging. Even if it returns to the normal value, the discharge time cannot reach the normal discharge time, and the battery is judged to be aging.

　　d. Battery power-on measurement: Do not power on the UPS and do not connect to the mains power. First use a multimeter to measure whether the total voltage of the battery pack is within the rated value range. Do not leave the test leads. Keep an eye on the multimeter's instructions, and then connect the power button. If so When the total battery voltage immediately drops below the low-voltage protection value or even lower, the UPS automatically shuts down immediately, and the voltage immediately returns to the original value after shutting down. Determine battery aging.

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