How do I know if my iPod is dying or it's just the battery?

[RHG]

My iPod (3rd gen, firewire, 15 gig, purchased may '04) is recently acting very unstable. I don't know if the hard drive or the battery is dying. I'd rather buy a 3rd-party battery than a new iPod, but I'm not optimistic.

Here are some symptoms:
-often not found by the computer when I plug it in and doesn't sync (longstanding issue)
-more recently the battery life is very bad, and unit goes to 'check hard drive mode' very often. Sometimes, when I turn it on, all the settings are reset, and I even have to choose my language. And then, sometimes, I turn it on, and it appears that the hard drive is empty. So far it always comes back after a recharge and a few resets.

[Sherman Homan]

It certainly sounds like the symptoms of a dying battery, and given that it is three years old, the battery is at the end of its life cycle. You could go to the trouble and expense of replacing the battery only to discover that the hard drive is also failing. Sort of like an old car, do you replace the slipping tranny when the engine is starting to burn oil?

[Anti]

Batteries are cheap, so I'd try that. If it dies, you can buy a new disk for it for under a hundred dollars off ifixit.com, I think.