I have a MacBook and I did not take care of the battery properly. It started to shut down unexpectedly at around 20% and then even at 30%. I got a new battery and it seems to work fine; it lets me get down to 6%. The only problem is that even with the new battery, a warning does not pop up telling me that it is time to plug in my computer. I was waiting for it to come up when my computer was at 6%, and instead it just died. I don't know if I need to change some kind of setting or what. Any ideas on how to fix this?

  • 1
    Actually, your battery should be able to drain to 0%. Even then your battery still has some charge that it uses for save sleep to protect your data. Did you try calibrating your battery? You can do this once a month to optimize battery performance: support.apple.com/kb/ht1490
    – gentmatt
    Commented Nov 30, 2011 at 7:01
  • As far as I know, the battery warning only comes up when the battery icon is visible in the menu bar. Is this the case?
    – myhd
    Commented Aug 18, 2012 at 7:56

3 Answers 3


I had reset SMC several times and changed my battery once. Unfortunately, my MacBook did not show low battery warning anymore. Then I found SlimBatteryMonitor, it works for me. You can customize the percentage of battery (if drops below x%) to show the warning panel too.

  • Just a +1 for SlimBatteryMonitor. It's not perfect, but for a free and simple app, it's pretty great.
    – brandonjp
    Commented Jan 16, 2013 at 20:20

Try resetting the SMC. Details are listed here. You will notice that the symptom you described is listed on that page too as "The computer sleeps or shuts down unexpectedly."

One additional piece of advice. You only need to do this SMC reset once. Don't reset your SMC repeatedly and consecutively. That's not advisable.

  • 1
    Why is it not advisable to reset the SMC repeatedly? I could not find it in the description.
    – gentmatt
    Commented Nov 30, 2011 at 7:04
  • 2
    Had 4 friends who unintentionally messed up their MB and MBP logic board (requiring logic board change at the Apple Store ) after repeated consecutive resetting of the SMC. Could be limited to only laptops, at this point only 4 data points. Commented Nov 30, 2011 at 7:15
  • Uhh, that's expensive.
    – gentmatt
    Commented Nov 30, 2011 at 7:19
  • Yep, I "killed" a MB once this way too. 8( Commented Nov 30, 2011 at 7:20

I'd really recommend Battery Medic

It's completely free and supports notifications based on a battery threshold that you can set

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