Experiment to determine the amount of energy that could be liberated from a cell

[Open Intelligence]

Take readings of voltage against current at different times and then plot a graph of power against time.

Energy in the cell = area under the graph

Draw a circuit with the following components: variable resistor, ammeter in series, voltmeter in parallel to a bulb, a switch and electrical wires.

Make sure you use a new cell.
Take readings after every 5 minutes (this might depend on the rate at which the chemical energy in the battery is being consumed).