Service Battery?

You can continue using the computer connected to the power adapter (and maybe with the battery), but the battery is damaged and its life has ended, so you should take the Mac to an Apple Store or reseller to get the battery replaced.

To know how much it will cost, see "Battery Replacement" > http://support.apple.com/kb/index?page=servicefaq&geo=United_States&product=Macn otebooks

Macbooks *can* run with bad battery that is doing no work. But even wall power may not be enough for some heavier operations and those heavy operations may slow down.

But you also have the issue of bad battery going from "dead" to "swelling and leaking chemicals".

I would just get it replaced. Apple replaces for $129. Follow the "mMore Like This" to the right and you shol find some links to less expensive sources.

There is no way to gtell how long the battery will last before it goes. I would get to an Apple store immediately to repace it before it causes more issues for your book. Don't chance it.

You are welcome