MacBook Unibody 2009 Battery Issue I have a MacBook Unibody 2009 and am facing a weird issue.

My laptop only works when it's connected to a power source but not on battery.

As most of us would, I thought the battery was gone so I bought a new battery. However, after charging it I still had the same issue.

So, I took it to a repair person whom I know and he told me it's some issue on the motherboard. Now I am not very sure how accurate his diagnosis is.

Does anybody here know of or have a similar issue concerning MacBooks? Can anyone share some information on this?
Have you tried resetting the SMC?

Reset the SMC

It's easy to reset your computer's System Management Controller (SMC). The instructions for resetting the SMC on a MacBook depends on two things:


Does your device run from a removable battery? (Yes in your case)
Does your device run from a built-in battery?


Now, for the sake of others who may come here looking for answers to the same issue, I will provide the process for both. 

For MacBook Pros, MacBooks etc that you can remove the battery from, here’s what you do:


Shut down your computer
Disconnect the MagSafe plug (power cable) from the computer
Remove the battery
Press the power button for 5 seconds and release
Put the battery back in
Reconnect the MagSafe cord (or power cable)
Turn your computer back on with the power button


For MacBook Pros, MacBook Airs, and MacBooks where you can’t remove the battery on your own (i.e. it's a built-in battery), here’s what you do:


Shut down your computer
Keep the MagSafe adapter (power cable) plugged in.
Press at the same time shiftoptioncontrol (on the left side of the keyboard) and the power button
Let go
Turn your computer back on with the power button.


Hope this helps. Please report back and let us know.

Reset your PRAM/NVRAM

Older Macs had what's called Parameter RAM (PRAM), newer Macs use Non-Volatile Random-Access Memory (NVRAM). It may be worth you also resetting this. Here’s how to:


Shut down your machine. Yes, a full shut down, not just logging out.
Press the power button and then press the commandoptionpr keys. You have to make sure you press these keys before the gray screen appears or it won’t work.
Hold those keys down until your Mac reboots again and you here the startup chime.
Let go of the keys and let your Mac reboot normally.


Note: When you log back in you may need to readjust some of your system preferences (e.g. mouse speed, time and date/timezone, etc).