Master Electrician

A battery is a device that converts chemical energy into electrical energy through electrochemical reactions. Every battery consists of one or more electrochemical cells, each containing three essential components: an anode (negative electrode), a cathode (positive electrode), and an electrolyte (ionic conductor).

The anode undergoes oxidation during discharge, releasing electrons into the external circuit. The cathode undergoes reduction, accepting electrons from the external circuit. The electrolyte provides a medium for ion transfer between electrodes while preventing direct electron flow, which would short-circuit the cell.

Secondary cells are rechargeable batteries capable of being restored to full capacity by applying an external electrical current in the reverse direction of discharge. The electrochemical reactions in secondary cells are reversible. Common examples include lead-acid batteries, nickel-cadmium (NiCd), nickel-metal hydride (NiMH), and lithium-ion (Li-ion) batteries.