Experiment 5 - The Ideal Battery

Up to this point you were not cerncerned about the batteries. To you they delivered at all times a constant voltage of 9 or 1.5 volts. You assumed to be using ideal batteries.

An ideal battery with 9 volt is characterized by the following properties...

• It provides a perfect, constant voltage of 9 volts.
• It has no electrical resistance (0 Ω).

With an ideal battery only the connected load determines how much current is flowing.

An ideal battery with a load RL.

An ideal 9V battery provides the perfect voltage to the point at which the battery is exhausted.

Consider again the last experiment. With an ideal battery, with a capacity of 500 mAh, you would measure the following levels...

• At the load the entire voltage of 9 V is applied.
• A current of 0.9 A flows.
• After 33 minutes the voltage suddenly goes to 0 V and current ceases to flow. The battery is dead.

You realize that it does not correspond with reality. In the next experiments you get to know real batteries.