What are the preventive measures for the thermal runaway of the UPS battery

The thermal runaway problem of UPS battery must be highly valued. Although the battery itself is constantly heating up and the heat dissipation is difficult, but as long as the appropriate measures are taken and serious maintenance, the thermal runaway can be prevented.

1. Preventive measures for thermal runaway control of UPS battery

Battery thermal runaway refers to the battery charging current at constant voltage charging and UPS battery temperature has a cumulative enhancement effect, and gradually damage the battery. Thermal runaway of the battery will make the battery quickly lose water, and the electrolyte in the AGM separator will quickly dry up, eventually making the battery ineffective.

1.1 Charging equipment shall have temperature compensation function or current limit;

1.2 Strictly control the quality of the safety valve to make the gas inside the battery discharged normally;

1.3 The UPS battery should be set in a well-ventilated position and control the UPS battery temperature.

2. How to prevent the battery from thermal runaway

2.1 Select and adjust the floating charge voltage correctly in time.

2.2 The oxygen recombination is performed on the negative electrode, thus the temperature is the highest. Moreover, the pole and plate grid are metal, is a good thermal conductor, it is certainly more sensitive to the battery temperature increase than the battery container, so when charging it needs to constantly monitor the negative pole temperature, especially in summer or noon, pay special attention to whether the battery temperature rises.

2.3 The charging equipment shall have the temperature compensation and current limiting function.

2.4 Strictly control the quality of the safety valve to avoid failure and ensure the normal discharge of gas inside the battery.

3. Causes of UPS battery thermal runaway

There are many reasons for thermal runaway of UPS battery, high charging voltage, large gas volume, will lead to thermal runaway. If a single battery in the battery group has serious thermal runaway, and the constant voltage value of charging is unchanged, the other single batteries will also appear relatively high charging voltage, resulting in thermal runaway problem. The specific analysis is as follows:

3.1 Compact assembly causes heat dissipation difficulties

For compact assembled batteries, the electrolyte is stored in a porous separator, which makes it difficult to dissipate heat. It is not like ordinary lead acid battery can stir electrolyte when charging gassing, is conducive to heat dissipation. When there is a local short circuit inside the battery, the battery temperature rises higher.

3.2 In summer, the high temperature of floating charging current will increase

If the floating charge voltage is not reduced in time, the battery temperature will rise rapidly. Charging voltage is too high, the gas precipitation volume is too large and produce excessive oxygen cycle. If there is micro short circuit inside a single battery of battery group, it is also equivalent to increasing the charging voltage.

3.3 Safety valve is not sealed well or the open valve pressure is too low

The phenomenon of thermal runaway is very typical for battery. The direct consequence of thermal runaway is that the internal electrolyte of UPS battery dries up, the internal resistance of UPS battery is abnormal, the battery case deforms and expands, even breaks, and emits a large amount of acid gas. Battery fire and explosion is a more common thermal runaway hazard performance of power battery system, the impact is also more serious, not only will cause property loss and environmental damage, and even will cause personal injury or life danger.