Batteries are a collection of cells that forces a current through an electrical circuit. Batteries have both positive and negative sides. Electrons are pushed out of the negative side (the anode) and flow into the positive side (the cathode).

Batteries are represented in circuit diagrams as two lines one bigger and one smaller. The bigger line represents the positive terminal and the smaller line represents the negative terminal.

Example circuit diagrams of an battery

Terminal Voltage

In non-ideal batteries there is a small amount of resistance which decreases the voltage output of the battery.

In non-ideal batteries there is a small amount of resistance which decreases the voltage output of the battery. With the terminal voltage, , of the battery is given by

• Definitions
  • is the elecromotive force of the battery (measured in volts)
  • is the current the battery is supplying (measured in amps)
  • The internal resistance of the battery (measured in ohms)