battery life

Battery life

In this experiment an electrical cell is tested to exhaustion. The cell might be a dry-cell, an alkaline cell or a lead-acid accumulator. The decreasing voltage is measured over a (long) period of time and the software will show this as a graph of voltage against time. A light sensor could be used instead of a voltage sensor.

Apparatus
1.5V dry cells, lamp, switch, leads, voltage sensor, interface.

Setting up
Connect up the circuit as shown – disconnect the battery for the moment. Connect the sensor to socket 1 on the interface.
Some systems recognise the sensors you attach automatically, in others you do this yourself. If the voltage sensor has multiple ranges, use the 2V range.

Recording the data
Connect up the battery. Record for around 48 hours. Repeat using a different type of battery.

Using the results
How does the graph show the decay of the battery?
How do different batteries decay with time?
What uses would you recommend for each type of battery?
Find out if temperature affects the performance or recovery of the battery?
Save your data on disk. Print the graphs.

Using a data logger
As an alternative, a data logger can be used to collect the data independently of the computer:

Set up the circuit as shown. Connect the sensor to socket 1 on the data logger. If you can, set the range on the sensor to 2V.
Press the button which starts the data logger recording.
When the cell is exhausted, get your software to transfer data from the data logger.