I recently installed a Crucial SSD into my Macbook Pro (2.66 GHz Intel Core i7), and now the performance of my battery is probably about 50% of what it used to be.

I've tried to reset the PRAM, but the OS loads so quickly that it I've never been able to trigger, even though I'm quick with hitting the keys.

Any suggestions for improving performance, and/or resetting the PRAM?



Modern Macintosh computers store very little information in PRAM so resetting it is seldom a useful troubleshooting step.

Have you checked the condition of the battery using System Information? (It's in the Utilities folder and also accessible from the menu: [Apple] > About this Mac > More Info… > System Report —assuming you're running Lion)

If you're seeing Service Battery under the Hardware > Power:Battery Information/Health Information section that's probably your issue.

System Information

You might improve the battery life with a System Mangement Controller reset. Assuming your MacBook Pro doesn't have a removable battery, the SMC reset procedure is:

Shut down the computer. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time. Release all the keys and the power button at the same time. 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.

  • Not only is that not a healthy battery, it only has 57 cycles on it so it's probably defective. If the computer were under warranty Apple would replace it for free. – Richard Jan 27 '12 at 3:41
  • You might call up the vendor and see if they could ship you a second drive (perhaps a used one / return / loaner) just to rule out a bad drive? All but the most recent SSD generally use more energy than spinning drives in normal use - might yours be drawing more current by design than the older HDD? – bmike Jan 27 '12 at 3:48
  • @Richard That's my battery. My MacBook Pro is plugged in to the wall all the time. Apple has replaced the battery three times, (twice out of warranty) and the last time the Apple Store manager specifically told me that that would be the last time. (No complaints, I was prepared to buy a battery.) I use the iPad when I'm on the go, so I haven't bothered to replace this one. – jaberg Jan 27 '12 at 3:55
  • Wow, that's a lot of defective Sony batteries or, there REALLY is a problem with using these types of computers plugged in 100% of the time. In my last three MBPs I've only had two battery issues (stopped holding a charge with low cycle counts) and both were dealt with within AppleCare and the new batteries worked for the rest of the life of the computer. I do use my computers on battery power for part of every day and it may be that that helps. I figured it increased the cycle count and I'd be getting new batteries yearly but it hasn't worked that way in my experience. – Richard Jan 27 '12 at 11:35
  • I checked the battery health, and it says "Normal" - Cycle count is at 86. – mikebmassey Feb 2 '12 at 20:34

Any electric device that has a rechargeable battery will face the same issue if you overcharge the device. If you overcharge, you'll short the life of the battery and if you leave it charged for too long it might cause a fire.

I recommend you charge any electric device that has rechargeable battery to 95-98% and unplug it. In general, rechargeable battery life will decrease but if overcharge, you help short the life faster. To avoid replacing the battery within a year or so, charge to 90-98% and unplug.

Also do not use your device or put it in a hot area. If your device becomes too hot put it away to cool it off. Heat decreases your device's battery life. If you want to charge the battery the whole time, you must remove the battery to avoid overcharge. However, most Apple laptops do not have removable battery so you're better off by unplugging it between 95-98%.


To reset PRAM you need to press and hold cmd+optn/alt+p+r right after pressing power button and wait till it restarts with startup chime.

This shortcut triggers PRAM reset during POST procedure. It doesn't matter how fast or slow your disk is because it happens before any disk activity at all. Try press the combination after you send system to reboot from booted state.

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