Shutting down without warning

[AppleDuck]

My MacBook recently started shutting down without giving the battery warning. It consistently does it at 8% battery left. I'm running OSX Leopard and the computer is 3 years, 4 months old. AppleCare ran out 4 months ago.

According to both Coconut Battery and the system profiler the battery's condition is good.

When it does this I get a shutdown cause of -128, which I have googled and cannot seem to find anywhere.

Does anyone know of any way to fix this without buying a new battery? The battery still holds 82% capacity so I don't want to replace it.

 

[GGJstudios]

My MacBook recently started shutting down without giving the battery warning. It consistently does it at 8% battery left. I'm running OSX Leopard and the computer is 3 years, 4 months old. AppleCare ran out 4 months ago.

According to both Coconut Battery and the system profiler the battery's condition is good.

When it does this I get a shutdown cause of -128, which I have googled and cannot seem to find anywhere.

Does anyone know of any way to fix this without buying a new battery? The battery still holds 82% capacity so I don't want to replace it.

Try calibrating your battery, if you haven't done so recently. You'll find the steps in the CALIBRATION section of the following link.

The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.

Apple Notebook Battery FAQ​

 

[AppleDuck]

Thanks for the link. I calibrated the battery and now I occasionally get the battery warning, but not always. It doesn't go to sleep when it dies, though. Instead it turns off completely.

Not a huge deal or anything, but if anyone has any other ideas, that'd be great.

 

[RRutter]

Thanks for the link. I calibrated the battery and now I occasionally get the battery warning, but not always. It doesn't go to sleep when it dies, though. Instead it turns off completely.

Not a huge deal or anything, but if anyone has any other ideas, that'd be great.

Weird, I've been having the same exact problem on my MB also at 8%. Even weirder, it's a 1-week old battery purchased from Amazon. Needless to say the battery still works great, I typically try and keep it charged above my reserve battery limit and that does the trick!!