Discharge of lead-acid battery:
When the positive and negative plates of the lead-acid battery are immersed in the electrolyte, a static electromotive force of about 2.1V will be generated between the positive and negative plates. At this time, if the load is connected, the current will flow from the positive pole of the battery through the external circuit to the negative pole of the battery under the action of the electromotive force. This process is called discharge. The discharge process of the battery is a process in which chemical energy is transformed into electrical energy.
During discharge, PB02 (lead dioxide) on the positive plate and Pb (lead) on the negative plate react with h2s04 (sulfuric acid) in the electrolyte to form lead sulfate (pbs04), which is deposited on the positive and negative plates. H2s04 in the electrolyte decreases continuously and the density decreases.
Charging of lead-acid battery:
During charging, the positive and negative poles of the battery are respectively connected with the positive and negative poles of the DC power supply. When the terminal voltage of the charging power supply is higher than the electromotive force of the battery, under the action of the electric field, the current flows from the positive pole of the battery to the negative pole. This process is called charging. The charging process of storage battery is the process of converting electric energy into chemical energy.
During charging, pbs04 on the positive and negative plates is reduced to PB02 and Pb, h2s04 in the electrolyte increases and the density increases.
The state of the battery can be visually inspected through the densitometer. Generally speaking, the electric eye of the densitometer shows:
Green: normal use of battery;
Black: supplementary power is required;
White: the battery needs to be replaced
However, the electric eye of the densimeter only indicates the state of one cell of the battery. To judge the state of the whole battery, it is necessary to use the multimeter and other detection tools- Generally speaking, the normal voltage of a fully charged battery is 12.6-12.8 v. if the voltage is lower than 12 V, it needs to be recharged; If the voltage is still lower than 12V after charging, the battery needs to be replaced.
