View Full Version : Is this a normal battery capacity?

12th June 2010, 04:38 PM
I have a MBP 13" (previous revision). Bought Sept 09. Getting about 5 hours out of it (at best) with just word editing, sleeping, bit of wifi web browsing, rightness anywhere from medium to high.

I'm not so sure if the battery is fine. I have spoken to apple on the phone and they seem to think it's fine, but I'm not so sure. I've reset the SMC and NVRAM and no change. Currently calibrating it now (I calibrate it pretty often).

Cycle count: 83

Battery capacity: 4795mAh

After the first few days I found the battery life dropped from something like 5400mah to 5200mah within the first few charges, rang apple but they said it's okay.

Does it all sound fine? I'd especially appreciate advice from people with similar machines/battery cycles. I have booked a genius appointment for Monday, but might cancel it if unnecessary.


Shaun R
12th June 2010, 05:16 PM
I think that's probably normal.
Apple do their tests based on "best possible in theory" - this means WiFi off, brightness at low, probably no apps running - just set to remain "awake", and time how long it lasts.

On my current model 13" (10 hour battery), it *actually* gets 7-8 hours light usage on medium brightness and just light WiFi Safari web browsing.

If you use Flash at all, the battery disappears before you can click your fingers. If you watch YouTube in Safari, go to YouTube - Broadcast Yourself. (http://youtube.com/html5) and join the HTML5 beta - it's far far better. On Vimeo, just click "Switch to HTML5 player" underneath the video (the setting is saved).

A 1080p Flash video on YouTube eats 90% of my CPU & battery disappears crazy fast. HTML5 uses around 5% CPU and the effect on battery life is negligible.

Good luck!

PS: I also experienced the rapid drop in max capacity/current capacity in the first 4 cycles - it's normal, I guess.

13th June 2010, 06:02 AM
I wouldn't be too worried, 5 hours sounds about normal from what I have found on various internet forums. I have the same sort of machine (13" 2009 MBP, 2.13GHz) and get 4.5 - 5hours of run time off the battery. I am at 68 battery cycles and a max capacity of 5420mAh according to Coconut Battery. I have calibrated it maybe 3 times because I thought my run time was a bit on the low side, but I found my main culprit was the screen brightness which I now keep at about 50% when on battery.

I did read somewhere that the critical point when Apple would replace the battery under Apple care was the battery dropping to 80% capacity, which would be about 4300mAh, after a certain number of cycles but I can't find the link to it at the moment. Maybe try and google that and see if you can track it down.
- Berwyck

13th June 2010, 09:30 AM
Just finished calibrating, says I have a total of 4402mAh! Not good, will take it in tomorrow. IState Nano is saying that's exactly 80% of original capacity - hmmm. Apply say
A properly maintained Apple notebook battery is designed to retain up to 80 percent of its original capacity after 300 full charge and discharge cycles. It has been regularly calibrated and never abused...hopefully this will warrant a replacement.