I do apologize for the ignorance that I'm sure is imbedded in this question, but I'd like to understand the exact point at which the following argument goes wrong:
1) A battery (let's say an ordinary flashlight battery) maintains a voltage between its positive and negative terminals.
2) The only way to maintain a voltage is by maintaining a charge distribution. Therefore, at least one of the terminals on that battery carries a non-zero net charge.
3) If a terminal carries a non-zero net charge, I ought to be able to use it to pick up a paper clip.
Nevertheless, my flashlight batteries do not pick up paper clips. Is this because the charge is too small or because (at least) one of my three points is dreadfully wrong?
Answer
Richard Terrett's comment gives the correct answer: Richard, you should post it as an answer so people can upvote it.
A battery does indeed have excess charge at it's terminals, and the charge is simply given by the usual equation Q = CV, where C is the capacitance of the battery and V the voltage. However both the capacitance and the voltage of a typical domestic battery are small so the net charge is negligable.
However the reason a battery won't pick up scraps of paper is that the voltage is small. If you do the usual party trick of rubbing a ballon on a pullover you can charge the balloon to several thousand volts. If you only charged the ballon to 1.5V it wouldn't pick up small bits of paper let alone a paperclip.
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