The battery of a toy robot is assembled using a metal sheet and a carbon sheet separated by a sheet of fabric. This battery is connected with an electric motor. After adding salt solution to the battery container the toy robot speeds away.(for more see below).
To measure voltage and current the metal und carbon sheets are connected with a digital multimeter and dipped into salt solution. During the measurement of current gas bubbles are formed at the metal sheet. For more measurements of voltages, the metall sheet is replaced by another metal and after that the carbon sheet is replaced by a second metal.
First publication: 13.12.2013 last modification: 28.12.2013