DC Circuits Study Notes: How Batteries Store and Deliver Electrical Energy

battery

A device that converts chemical potential energy into electrical energy.

chemical potential energy

Energy stored in the arrangement of chemicals, used in batteries to generate power.

electrochemical cell

A single unit in a battery consisting of two electrodes, an electrolyte, and a separator.

anode

The electrode where oxidation occurs and electrons are released in a battery.

cathode

The electrode where reduction occurs and electrons are accepted in a battery.

separator

A component that prevents electrical contact between electrodes while allowing ion flow.

electrolyte

A medium that allows ions to move within a battery, can be liquid, gel, or solid.

discharging

The process of a battery delivering energy to an external circuit.

charging

The process of restoring a battery's energy by forcing current in the opposite direction.

potential difference (voltage)

The difference in electric potential energy per charge between two points in a circuit.

emf (electromotive force)

The energy supplied per unit charge by a battery, measured in volts.

terminal voltage

The voltage across the terminals of a battery, which can vary under load.

internal resistance

The resistance within a battery that causes energy loss when current flows.

power (P)

The rate at which energy is transferred, given by the formula P=IV.

current (I)

The flow of electric charge, measured in amperes (A).

capacity

The total charge a battery can deliver, often expressed in ampere-hours (Ah) or milliampere-hours (mAh).

primary cell

A non-rechargeable battery that cannot reverse its chemical reactions once discharged.

secondary cell

A rechargeable battery that allows its chemical reactions to be reversed.

charge (Q)

A measure of electric charge in coulombs (C), related to current and time.

excess electrons

An accumulation of electrons at one terminal of a battery, making it negatively charged.

deficit of electrons

A lack of electrons at one terminal of a battery, making it positively charged.

Brownout

A temporary reduction in voltage level in an electrical power supply.

short circuit

A direct connection between the battery's terminals, causing excessive current flow and heat.

voltage sag

A drop in voltage under high load conditions due to internal resistance and chemical limitations.

chemical reaction

A process altering the arrangement of chemicals in a battery to release or store energy.

thermal energy

Energy dissipated as heat within a battery due to internal losses during current flow.

rechargeable battery

A battery designed to allow chemical reactions to reverse, restoring its original state.

electrical power

The rate of energy transfer in an electrical circuit, calculated as P=IV.