ipod nano doesn't stay charged

I wouldn't put the iPod on hold when it's not turned on. Also, don't go by the battery indicator or unplug it when the iPod reports it's full -- indicators are notoriously inaccurate on lithium ion batteries. Do a full discharge, and then plug the iPod in for a good 3 or 4 hours, completely ignoring the battery indicator since it will probably say it's full after 15 minutes -- it will continue to trickle charge slowly after that and it needs a good long time to do it.

Once your battery has been conditioned to be charged through its full range, its duration should slowly improve, and eventually the indicator will also 'learn' and get more accurate -- provided you didn't get unlucky and just get a bum unit.

P.S. Don't make a habit of doing a full discharge -- it's not that great for lithium batts. Apple recommends you top up the battery liberally and only let it run out fully every 30 charge cycles or so (again, to make sure it stays conditioned).

If it was fully discharged before you did this then it should have performed better afterwards if the battery is functioning properly and you are not using the iPod in a high-power way (like with your Brightness turned up over 50% or constantly playing videos which would deplete your battery in a few hours). And try the 'not putting it on hold when it's off' thing -- that's an unusual habit, I think, and not really the intent of the 'hold' function. It may be harmless but I wouldn't bet on it.

Try fully discharging it by actually letting it play through until it shuts off, instead of letting it die while its shut off. Then let it charge overnight. This is the closest you can get to a full reconditioning of the battery.

P.S. It will discharge more fully if you drain it with audio (which can continue on lower power) than if you use video.

I just checked and there seems to be some precedent for people noticing that keeping the hold switch on drains the battery more rapidly when the iPod is off. I don't think we can post URLs in here, but on ilounge I found at least two other people who reported this -- along with others who denied it and pointed to Apple saying it doesn't. I personally don't know one way or the other, but I do no this: NOT having the hold switch on when the iPod is off will definitely not drain your battery and the iPod is unlikely to turn on accidentally since the touch sensitivity of the click wheel is off.