Is short life of lead-acid batteries related to maintenance methods?

Battery inspection and maintenance

Battery maintenance is indispensable. Whether manual operation or maintenance, or automatic monitoring and management, abnormal battery failure or equipment systems that affect battery charging and discharging performance should be detected in time. Faults should be corrected actively to ensure the stable and reliable operation of the power system. Battery inspection and maintenance are divided into daily maintenance, quarterly maintenance and annual maintenance.

Daily maintenance
Make sure the surface of the battery is clean and dry.
Always pay attention to the changes of the environment temperature and appearance of the battery system; nbsp; nbsp; nbsp;
Ensure that the battery cabinet or battery room is clean, ventilated or well lit.

Quarterly maintenance
Visually inspect the cleanliness of the outer surface of the battery, the integrity of the shell and shell, whether the appearance of the battery has any protruding changes, and whether the battery is overheated.
Check the battery system points quarterly, test and record the ambient temperature of the battery system, which can represent the average temperature of the system. The temperature control system should be adjusted when the temperature is lower than or higher than 25 degrees C. If there is no temperature control system installed, the floating voltage should be adjusted; the total voltage of floating charge at battery end should be measured and recorded, and compared with the display value of panel instrument. If there are any differences, find out the reasons and correct them in time.

Measure and record the floating charge voltage of each battery in the system.  Under normal circumstances, it should be affirmative. If abnormality is found, the fluctuation in the range will find out the cause to be corrected; restorative discharge test is carried out, using false load or actual load to discharge, that is, to cut off the power supply and use battery to supply power. When the battery is found to be insufficient, the battery charges evenly. After equalization and charging, the capacity can not be restored. Batteries with low capacity should be replaced.

Annual maintenance

Repeat quarterly maintenance of all content;
Check all battery connection points and ensure safe and fast connection.
Several batteries were selected for internal resistance test. Because of the wireless relationship between the internal resistance and its capacity, the internal resistance of batteries can not be used to directly indicate the accurate capacity of batteries, but the resistance of internal batteries can be used as an indicator of the health status of batteries.
Several factors affecting battery life
Deep discharge
The discharge depth has a great influence on the cycle life of batteries. If the battery is discharged deeply, the cycle life will be shortened. Because the deep discharge of batteries with the same capacity means that the current is often charged and discharged with a large current. When the current is discharged or often under voltage, it can not be charged in time. The sulfate particles produced are large, the active substances of the plate can not be fully utilized, and the actual capacity of the battery will gradually decrease over a long period of time, affecting the normal operation of the battery. Long-term depletion is the main cause of battery failure and shortened life in solar photovoltaic systems, because solar photovoltaic systems are usually not easy to overcharge.
Discharge rate
The capacity of the 20-hour discharge rate is usually specified as the rated capacity of the battery. If the discharge rate is lower than the prescribed hour, the battery capacity can be higher than the rated value; if the discharge rate is higher than the prescribed hour, the discharge capacity is smaller than the rated capacity of the battery, and the discharge rate also affects the end of the battery. Voltage value. When the battery discharges, the electrochemical reaction current preferentially distributes on the surface closest to the main solution, resulting in the formation of lead sulfate on the surface of the electrode to block the internal of the porous electrode. In the case of high current discharge, the above problems are more prominent, so the discharge current becomes larger, the capacity given by the battery is smaller, and the terminal voltage value decreases faster, that is, the discharge termination voltage value increases with the discharge current.
On the other hand, the lower the discharge rate, the better. Some studies have shown that the long-term low discharge rate will increase significantly due to the formation of lead sulfate molecule. Stress will cause the plate to bend and the active material to fall off, which will also reduce the use of batteries. Life.
Outdoor temperature is too high
The rated capacity of the battery refers to the value of the battery at 25 degree C. It is generally believed that the working temperature of VRLA batteries is ideal in the range of 20 30 C. When the temperature of the battery is too low, the capacity of the battery decreases because the electrolyte does not react well with the active material of the electrode plate at low temperature. Reduced capacity will not meet the expected backup time and remain within the specified discharge depth, which can easily lead to excessive battery discharge. From the external parameters of the battery, voltage has a great relationship with temperature. For each temperature rise of 1 degree C, the voltage drop of a single cell decreases by 3 mV. That is to say, the voltage of lead-acid battery has negative temperature coefficient and its value is - 3mV /. For the same reason, the increase of ambient temperature tends to cause excessive discharge of batteries. High temperature can also lead to water loss and thermal runaway of batteries. Temperature is the main factor affecting the normal operation of batteries. In solar photovoltaic system, the controller usually needs to have temperature compensation function.