have you got a pair of old computer speakers lying around that you dont need?
want to make a decent iPod/mp3 amp?
these speakers are powered via a PP3 9V battery
snap on clip for 9V batter
soldering iron and solder
Step 1: disassemble speakers
your speakers might not be 9V, if there not you could possibly use AA batteries in series in aholder or use a gel cell, bit heavy though.
disassemble the speaker with volume and power input, unscrew it from the back, there should be a transformer attached to the back, this is what takes the 230V (110V) down to 9V or the working voltage for your speakers.
on the transformer it should say the primary and secondary voltage, the secondary voltage should be lower, 9V hopefully, if it is not 9V you may still be in luck, if it is 3V use two AA batteries, if its 6V use 4, if its 12V use either 8 AA batteries or a car battery or gel cell battery, look online for one.
however, if you want, you can put a batter inside if you have room, or outside if you dont, and put the speaker cases back together.