Electrochemical reactions in electrodes

The electrochemical reaction formula of the valve regulated lead acid battery is shown below. Charging is the process of connecting an external DC power source to a storage battery to charge, converting electrical energy into chemical energy and storing it. Discharge is the release of electrical energy from a battery to drive external devices.
When the VRLA battery is about to reach the peak of charging, the charging current is only used to decompose the water in the electrolyte. At this time, the positive electrode of the battery generates oxygen, and the negative electrode generates hydrogen. The gas will overflow from the battery, causing a decrease in the electrolyte. It is necessary to add water from time to time.
On the other hand, at the end of charging or under overcharge conditions, the charging energy is used to decompose water, and the oxygen generated by the positive electrode reacts with the spongy lead of the negative electrode, leaving a portion of the negative electrode in an unfilled state, inhibiting the generation of hydrogen gas in the negative electrode.
Service conditions
(1) Avoid direct contact between batteries and metal containers. Use acid resistant and heat resistant materials, otherwise they may cause smoke or combustion.
(2) Use the specified charger to charge under the specified conditions, otherwise it may cause the battery to overheat, deflate, leak, burn, or rupture.
(3) Do not install the battery in a sealed device, as this may cause the device to rupture.
(4) When using batteries in medical equipment, please install a backup power supply other than the main power supply, otherwise failure of the main power supply may cause injury.
(5) Keep the battery away from spark generating equipment, otherwise sparks may cause the battery to smoke or crack.
(6) Do not place the battery near a heat source (such as a transformer), as this can cause the battery to overheat, leak, burn, or rupture.
(7) When the number of batteries in an application exceeds one, please ensure that the connection between the batteries is correct, and that the connection to the charger or load is correct. Otherwise, it may cause battery breakage, combustion, or battery damage, and in some cases, it may also cause personal injury.
(8) Take special care not to let the battery hit your feet.
(9) The specified usage range of the battery is as follows. Exceeding this range may cause battery damage.
The normal operating range of the battery is 77. F (25 ℃)
After battery discharge (installed in the device): 5. F to 122. F (- 15 ℃ to 50 ℃)
After charging: 32. F to 104. F (0 ℃ to 40 ℃)
During storage: 5. F to 104. F (- 15 ℃ to 40 ℃)
(10) Do not place the battery installed on the locomotive in high temperature, direct sunlight, in front of the stove or fire, as this may cause battery leakage, fire, or breakage.
(11) Do not use the battery in a dusty area, which may cause a short circuit to the battery. When using batteries in dusty environments, they should be regularly inspected.