Battery Life Sank on Macbook Pro (2012) After Upgrading Hardware (?)

I recently purchased a new 2012 Macbook Pro, not the retina model, and have been loving it.  After a month or so of use, I decided to upgrade both the RAM and the hard drive because I wanted to squeeze every ounce of performance out of the machine that I could without paying the premiums that Apple charges for it’s upgraded parts.

After doing some research, I ended up purchasing a Crucial 256 GB m4 2.5-Inch Solid State Drive SATA 6Gb/s CT256M4SSD2 and a Corsair Vengeance 16 GB (2x8GB) DDR3 1600MHz PC3 240 Pin DIMM Memory CMZ16GX3M2A1600C10 kit from Amazon.  I considered using OCZ for the SSD since performance on that drive was rated higher, but after seeing the power requirements of the OCZ, I changed my mind and went back with the Crucial.  I also read some user reviews that said that the OCZ had compatibility issues the MacBooks.


I used SuperDuper to duplicate my drive onto the SSD.  The hardware swap was quick and easy taking about 10 minutes to do for both, but requiring a T-6 Torx driver to change out the hard drive.  The system came back up and ran perfectly and I enabled TRIM by using TrimEnabler (

A few days later, there was a problem when I unplugged and started using the system on battery power.  The battery icon became a countdown dropping numbers in very short order and only showing 2 hours or so of available battery starting from full, and all I was doing was browsing the web.  I was both perplexed and annoyed by this as I require a laptop that has good battery life, but I noticed that heat was being generated from processor side of the palm rest (lower left hand side) and wondered if it was my hardware upgrade, the data-cloning, or something unrelated.  I still am not quite sure why this happened, but I’ll explain what I did to fix it.

Opening up Activity Monitor, one of the mac utilities, I noticed that the ‘mtmfs’ process was spiked at a consistent 96% while all other processes were nominal.  After doing a little digging, I read a post that suggested disabling Spotlight indexing of the local HD, rebooting, and then re-enabling.  I did so, the process dropped it’s peaks, and battery life was back to normal.  Here’s the quick steps:

1. Disable Spotlight for the local HD and any other attached drives.  System Preferences > Spotlight > Privacy (tab).  Click the + sign and add the HDs.


2. Reboot.

3. Re-Enable Spotlight on your drives. NOTE: Spotlight will have to re-index any drive that you’ve removed from the privacy list.

After this, the system was back to normal with my 5+ hours of battery life.  Again, I’m not sure what caused this behavior.  It could have been the hardware upgrades (drive being replaced with a clone) or it could have just developed due to something else I did, but the simple steps above fixed it.  Hopefully it doesn’t occur again.

I’m now running a VERY snappy MacBook Pro with 16GB RAM and a great SSD, with battery life back to expected ranges. Smile

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