MacBook wont run from battery

To reset your MacBook's battery and settings, you can try the following steps:

1. Resetting the System Management Controller (SMC): a. Shut down your MacBook. b. Press and hold the Shift + Control + Option keys on the left side of the keyboard and the power button at the same time for 10 seconds. c. Release all the keys and the power button at the same time, then press the power button again to turn on your MacBook.
2. Resetting the NVRAM (non-volatile random-access memory): a. Shut down your MacBook. b. Press the power button to turn on your MacBook, then immediately press and hold the Command + Option + P + R keys. c. Keep holding the keys until you hear the startup sound twice. d. Release the keys and let your MacBook start up normally.
3. Calibrating your MacBook battery: a. Charge your MacBook battery to 100%. b. Use your MacBook until the battery runs out of power and your MacBook shuts down. c. Leave your MacBook off and unplugged for at least 5 hours. d. Connect your MacBook to the power adapter and charge it to 100%.

These steps should help reset your MacBook's battery and settings.

First step would be to Reset Your Mac's SMC
The method for resetting your Mac's SMC depends on the type of Mac you have. All SMC reset instructions require shutting down your Mac first. If your Mac fails to shut down, try pressing and holding the power button until the Mac shuts down, which usually takes 10 seconds or so.

Mac portables with user-removable batteries (MacBook and most MacBook Pros):

1.Shut down your Mac.
2.Disconnect your Mac portable from its MagSafe connector.
3.Remove the battery.
4.Press and hold the power button for at least 5 seconds.
5.Release the power button.
6.Re-install the battery.
7.Reconnect the MagSafe connector.
8.Turn your Mac on.
Mac portables with non-user-removable batteries (MacBook Air and some late 2009 MacBook Pro models):

1.Shut down your Mac.
2.Connect the MagSafe power adapter to your Mac and to a power outlet.
3.On the built-in keyboard (this will not work from an external keyboard), simultaneously press and hold the left shift, control, and option keys while you press the power button. Release all keys at the same time.
4.Press the power button to start your Mac.

Mac desktops (Mac Pro, iMac, Mac mini):

1.Shut down your Mac.
2.Unplug your Mac's power cord.
3.Press and hold the Mac's power button for 15 seconds.
4.Release the power button.
5.Reconnect your Mac's power cord.
6.Wait five seconds.
7.Start your Mac by pressing the power button.

Alternative SMC reset for Mac Pro:

If you have a Mac Pro that isn't responding to the normal SMC reset as described above, you can force a manual SMC reset by using the SMC reset button located on the Mac Pro's motherboard.

1.Shut down your Mac.
2.Unplug the Mac's power cord.
3.Open the Mac Pro's side access panel.
4.Just below the Drive 4 sled and adjacent to the top PCI-e slot is a small button labeled SMC. Press and hold this button for 10 seconds.
5.Close the Mac Pro's side door.
6.Reconnect your Mac's power cord.
7.Wait five seconds.
8.Start your Mac by pressing the power button.
Now that you have reset the SMC on your Mac, it should be back to operating as you expect. If the SMC reset didn't fix your problems, you can try combining it with a PRAM reset. Although the PRAM works differently than the SMC, it can, depending on your Mac model, store a few bits of information that the SMC uses.

Assuming your computer has a built-in iSight camera - which should be all Macs made since 2006 except for the Mac Mini and Mac Pro (not MacBOOK Pro!) - your camera

a) May not be being seen by the computer. Check Apple Menu > About This Mac > More Info > USB and see if "built-in iSight" is listed in the USB Device Tree. If it is, then it may be being used by another application that uses a webcam, like Skype, iChat, or what have you. If it IS NOT detected:

b) Try resetting your SMC:

Resetting the SMC on Mac portables with a battery you can remove
Note: Learn about removing the battery on MacBook and MacBook Pro.

1. Shut down the computer.
2. Disconnect the MagSafe power adapter from the computer, if it's connected.
3. Remove the battery.
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.

Resetting the SMC on portables with a battery you should not remove on your own
Note: Portable computers that have a battery you should not remove on your own include MacBook Pro (Early 2009) and later, all models of MacBook Air, and MacBook (Late 2009).

1. Shut down the computer.
2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
4. Release all the keys and the power button at the same time.
5. Press the power button to turn on the computer.
   Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.

Resetting the SMC for Mac Pro, Intel-based iMac, Intel-based Mac mini, or Intel-based Xserve

1. Shut down the computer.
2. Unplug the computer's power cord.
3. Wait fifteen seconds.
4. Attach the computer's power cord.
5. Wait five seconds, then press the power button to turn on the computer.

Good luck!

Your best bet is to reset the System Management Controller;
(I'm not sure if your model has a removable battery or not, so I'm providing both methods)

Resetting the SMC on Mac portables with a battery you can remove
Note: Learn about removing the battery on MacBook and MacBook Pro.

1. Shut down the computer.
2. Disconnect the MagSafe power adapter from the computer, if it's connected.
3. Remove the battery.
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.

Resetting the SMC on portables with a battery you should not remove on your own
Note: Portable computers that have a battery you should not remove on your own include MacBook Pro (Early 2009) and later, all models of MacBook Air, and MacBook (Late 2009).

1. Shut down the computer.
2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
4. Release all the keys and the power button at the same time.
5. Press the power button to turn on the computer.
   Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.

...and then reset the Parameter RAM:

1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.

If it is repeatedly beeping it sounds like a memory issue. you should try removing your memory one stick at a time and attempting to reboot.(remove one try to start, replace, remove other try to start). If it doesn't work with either stick try using a "known to be good" or new stick of memory and see if it starts. Here is a link explaining how to remove and change/upgrade your memory. Very simple really, involves removing the battery and removing a plate with three screws in it.

1. Insert OS X disc
2. shut down computer
3. hold down the "c" key
4. power on the computer
5. wait for the computer to boot from the disc
6. click install
7. go to the top and choose Utilities
8. open Disk Utilities
9. ERASE the hard drive, choose Mac OS Journaled as file system.
10. Go back to the install menu
11. follow the prompts
12. that's it! :)
    

Cable short. Replace the charger or you risk an exploding battery.

Ok Take out the battery and leave it out for about an hour. IN the time its out Run the laptop on AC power and then go to control panel, open power options, and remove the hibernation check, and the turn the system standby to never, then hit apply. Then turn you laptop off and re insert the battery. If you still get the shutdown where it wont run on battery, then you need to replace the battery.

After determining the battery health:
http://support.apple.com/kb/HT1519

Then calibrate the the battery:
http://support.apple.com/kb/HT1490