Design of a lemon battery

From the excellent site of Christian Loockx

The equipment

- One or more lemons (of course) - One or more copper blades (from a copper plumbing tube for instance) - One or more zinc blades (from old gutters or downpipes for instance) - Some pieces of electric wire (preferably more rigid single stranded wire ) - Crocodile clips - Small light diodes, digital clocks, piezoelectric buzzers, small engine, ...

The assembly

In order to make a "unit-battery", let's take a half a lemon and introduce it in a little non metallic vessel (or a cup). A piece of copper (which will be the POSITIVE terminal) is pressed into the lemon and, at a distance of 1 to 2 cm also a piece of zinc (which will become the NEGATIVE terminal). Our "unit-battery" is now finished. If we connect (respecting the signs) the terminals of a voltmeter to the zinc and copper blades, we observe a potential difference (called "Voltage"). If we want to gain more power in order to operate small electric or electronic devices, we have to make more "unit-batteries" and connect them in SERIES So we have realised a "bio" battery ...