Q: is it gone?

Power or other problems related to unexpected system sleep, shutdown, lights or fans call for an SMC reset. Try that.

Resetting the SMC on Mac portables with a battery you can remove

1. Shut down the computer.
2. Disconnect the MagSafe power adapter from the computer, if it's connected.
3. Remove the battery (to remove the battery - click here: MacBook or MacBook Pro).
4. Press and hold the power button for 5 seconds.
5. Release the power button.
6. Reconnect the battery and MagSafe power adapter.
7. Press the power button to turn on the computer.

Here you go:

http://store.apple.com/us/product/MA561LL/A/rechargeable-battery-13-inch-macbook -white

There are plenty of aftermarket battery vendors. I do not recommend them since I have found Apple batteries last the longest.

If you want to consider another source here is one:

http://www.powerbookmedic.com/13-inch-MacBook-Rechargeable-Battery-NEW-p-17004.h tml

You can get a new third party battery fairly cheap on eBay. Every MacBook from 2006 through Mid 2009 except the Late 2008 Aluminum Unibody and the Late 2009 and 2010 White Unibodies use the same A1185 battery.

White Batteries http://shop.ebay.com/i.html?_nkw=macbook+white+battery&_sacat=0&LH_BIN=1&_sop=12 &_dmpt=Laptop_Batteries&_odkw=macbook+black+battery&_osacat=0&_trksid=p3286.c0. m 270.l1313

Or for $129 from The Apple Store  http://store.apple.com/us/product/MA566LL/A?mco=MTY3ODQ5OTY