Sudden Drop (Massive) in Battery Health/Life

[thatoneguy82]

I have a 17" mid-2010 MBP. It was purchased May 2010, never had a hardware problem since now. I have Applecare until May 2013, but thought I'd get some input here first. Also since I'm lazy to switch out the RAM and HDD/SSD/SuperDrive.

Today, out of pure coincidence, I looked at the battery health through iStat menus and noticed that it had dropped significantly! Last week it was around 95%! Nothing major has happened or anything at all. In fact, I haven't even restarted or turned off my computer for the last 14 days. I restarted and still the same bad health. It some times goes to 84/86, but that's probably negligible.

Can anyone shed some light on this? I really like this MBP and wouldn't want a new case or new anything (battery notwithstanding) that will sully it. Thanks!


Images from iStat menu bar and System info:

 

[GGJstudios]

Today, out of pure coincidence, I looked at the battery health through iStat menus and noticed that it had dropped significantly! Last week it was around 95%! Nothing major has happened or anything at all. In fact, I haven't even restarted or turned off my computer for the last 14 days. I restarted and still the same bad health. It some times goes to 84/86, but that's probably negligible.

It is perfectly normal if your battery health (maximum capacity) is more or less than 100%, even when brand new, or if it fluctuates up or down over time. For further details, read the CHECKING STATUS AND HEALTH 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​

 

[thatoneguy82]

It is perfectly normal if your battery health (maximum capacity) is more or less than 100%, even when brand new, or if it fluctuates up or down over time. For further details, read the CHECKING STATUS AND HEALTH 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​

Thanks, I sort of had idea of that, definitely not the entire information you listed. The thing that concerns me most is the ~10% drop in battery health in days, with no change in hardware, software installs/uninstalls, hasn't been rebooted.

I called Apple Support and told them of my situation. They really didn't "trust" iStat as the end all, be all of battery percentages. However, based on my usage to charge experience and charge cycles, he was concerned. It now takes me about 2-2.5hours (if I'm lucky) to get use and takes about 1.5-2 hours to fully charge.

I guess I'll have to go to the Genius Bar after all. So lazy to re-install to default configuration. I have decals on my MBP - that shouldn't matter or be removed, right?

 

[GGJstudios]

I guess I'll have to go to the Genius Bar after all. So lazy to re-install to default configuration. I have decals on my MBP - that shouldn't matter or be removed, right?

iStat Pro is reliable to provide accurate stats. It doesn't hurt, however, to have Apple test the battery to see if it's defective. Many times, they won't even check if the battery health isn't under 80%. As for the decals, no, it won't make any difference, as they have no effect on warranty.