My battery icon has an X over it

I have similar results, however battery is installed and works without plug! It will ocassionally have a power percentage but even unplugged, it works fine except the X and these settings.

I have a Macbook Pro that is about 2 years old. I have been having the same issue for about a month and a half now. It happens on and off, usually after taking my computer with me to class, which makes me think my backpack jostling the computer is causing a battery connection issue. However, I took my laptop to the Genius Bar and he said my battery looked great and he didnt see any connection issues at the time. It started acting up again and I did a chat with a representative and he seemed very concerned and told me to take it back to the Genius Bar ASAP. As a college student, I havent had time to take it to get checked in because I can't be without my laptop for several days. It started acting up again yesterday by showing the X and shutting off as soon as i unplug it from the charger. Any suggestions?

Only what the represenatitve said, Book a Genius appointment ASAP

I have an early 2011 MacBook Pro. I had a similar problem. Suddenly, although I had checked recently my battery in system information and had over 5,000 charges left, I got an x over my battery icon. I tried to reset the SMC but that didn't work. So I removed the back of my MacBook Pro and I noticee the battery seemed to have a reset button. I pressed it, closed up the case and restarted the computer. My battery now registered at 100%. When I tried to recharge my battery later it wouldn't recharge, the light remained green on the charger. So I turned off the computer kept it plugged in and reset the SMC the light changed from green to orange. I started the computer back up and everything seems to be running as it should. The link to resetting the SMC is:

Resetting the System Management Controller (SMC) on your Mac - Apple Support

Good luck on your finicky MAC.

I just got off the phone with an Apple Tech and this is what we did and it fixed my x in my battery icon as well as sluggish performance. My Macbook wouldn't recognize my battery so here's one solution:

1. Power down
2. Hold “Command”, “Option”, “Shift” and power button simultaneously for 15 seconds (it won't appear to be doing anything)
3. Hit power button, then immediately hold down “P” and “R” until it chimes twice

Try killing your laptop and then charging it. I did that and afterwards my laptop was completely normal.