Chemistry is very wonderful subject to explore. You can even produce electric current with two pairs of different metal (we will refer these metals as electrodes) with a solution (electrolyte). Of course you will need a pair of black and white wire and a voltmeter to detect the current.

Here's how its done...

Prepare a salt solution containing one of the metal ions. Then immerse both metals into the solution. Make sure the metals do not make contact with each other. Then connect one of the wire to one of the metal and do the same thing with the other metal. After that, connect the other end of the wire to the voltmeter and see how the voltmeter reading increase. If in some case you connect them at the wrong poles/terminals, just change the poles/terminals.

Here, I use a copper and magnesium metal with copper(II) solution.

The voltmeter reading shows 1.5 V. Well, if you want the experiment to be more interesting - build a series of the voltaic cell to produce higher voltage and try to light a 6.0 V with it.

Hm... here what I did. Prepare another 3 beaker filled with the same solution and get more copper and magnesium metal. Then, I connect the positive terminal to the negative terminal of the other beaker. Do this to each beaker and walllllaaaa.... 4.75 V was produced. 

Well... the voltage produced from a voltaic cell can be increased using this method but it will reduce somehow when the concentration of ions in the (electrolyte decreased as the result of transferring and acceptance of electrons at both electrodes.

You might want to try these out!!!

REMARKS: This is just an experiment!!! It is fun to explore new things....