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2022

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07

What are the precautions for battery thermal runaway?

Author:


The thermal runaway of the battery means that when the battery is charged at a constant voltage, the charging current and the temperature of the UPS battery have a cumulative enhancement effect, and the battery is gradually damaged. And it is difficult to dissipate heat, but with proper measures and careful maintenance, thermal runaway can be prevented.

Analysis of the causes of thermal runaway of UPS batteries:
1. The ambient temperature is too high or the voltage of the charging device is out of control
2. The charge of the battery increases too fast, the internal temperature rises, and the internal resistance of the battery drops
3. The charging current further increases (I=U/R), the charging capacity continues to increase, the internal resistance continues to decrease, the temperature continues to increase, and so on, until the battery case is seriously deformed and burst.​

UPS battery thermal runaway prevention measures:
1. Correct selection and timely adjustment of float voltage
2. The charging equipment should have temperature compensation function or current limit;
3. Strictly control the quality of the safety valve so that the gas inside the battery can be discharged normally;
4. The UPS battery should be set in a well-ventilated location, and the temperature of the UPS battery should be controlled.

The phenomenon of thermal runaway is very typical. The direct consequence of thermal runaway is that the electrolyte inside the UPS battery dries up, the internal resistance of the UPS battery is abnormal, the battery shell deforms and expands, or even ruptures, and a large amount of acid gas is emitted. Battery fire and explosion are the most common thermal runaway hazards in power battery systems, and the impact is even more serious. It will not only cause property damage and environmental damage, but even cause personal injury or danger to life

The most direct and effective measure is to install a battery on-line monitoring system for the battery pack to monitor the battery cell voltage, internal resistance, pole temperature, current, leakage and other important parameters online. Once a parameter is found to be abnormal or its change When the parameters are abnormal, it will immediately give an alarm, which can prompt the maintenance personnel to find problems or potential hidden dangers in time, so as to deal with them in time to ensure the reliability and safety of the UPS system.