My macbook pro has an X in the battery sign, and it will not run unless it is plugged in, why is this?

Question

Can someone please help I don't know what happened.
Battery Information:
  Model Information:
  Serial Number:          W012050PSD3BA
  Device Name:          bq20z451
  Pack Lot Code:          0000
  PCB Lot Code:          0000
  Firmware Version:          0201
  Hardware Revision:          000a
  Cell Revision:          0158
  Charge Information:
  Charge Remaining (mAh):          0
  Fully Charged:          No
  Charging:          No
  Full Charge Capacity (mAh):          0
  Health Information:
  Cycle Count:          0
  Battery Installed:          No
  Amperage (mA):          0
  Voltage (mV):          0
System Power Settings:
  AC Power:
  System Sleep Timer (Minutes):          10
  Disk Sleep Timer (Minutes):          10
  Display Sleep Timer (Minutes):          10
  Wake on AC Change:          No
  Wake on Clamshell Open:          Yes
  Wake on LAN:          Yes
  Current Power Source:          Yes
  Display Sleep Uses Dim:          Yes
  Battery Power:
  System Sleep Timer (Minutes):          10
  Disk Sleep Timer (Minutes):          10
  Display Sleep Timer (Minutes):          2
  Wake on AC Change:          No
  Wake on Clamshell Open:          Yes
  Display Sleep Uses Dim:          Yes
  Reduce Brightness:          Yes
Hardware Configuration:
  UPS Installed:          No
AC Charger Information:
  Connected:          Yes
  ID:          0x0100
  Wattage (W):          60
  Revision:          0x0000
  Family:          0x00ba
  Serial Number:          0x00782abb
  Charging:          No

Answer 1

I had this problem and went to the Apple Genius bar 3 times and everytime they said it was a logicboard failure.. they repaired my logicboard 3 times and within a week of use the x icon would show up.. and it would only run when the power adapter was plugged in.
But as i was fed up going back and forth to the Apple store.. I left the charger connected for about 3-4 days and one the 4th day I pressed the battery button on the side and Voila! It lit up the amount of battery charged.. Keep in mind that the battery light on the left hand side didnt lit up when I pressed the button when the x battery icon showed up
Not to sure how long this will last but I just checked my battery information and now it shows how much cycles and etc it has.. (when before it had all zeros)
I've found that the x battery icon only comes on when the battery is fully depleted (sometimes)!
Btw I have the early 2011 macbook pro 13" unibody model so I wasn't able to take out the battery beneath!
Hope this works!