Defective battery perhaps? try SMC reset and see how it goes.
What are you doing on it when it says it has 3 hours left?
Two thoughts.Hallo. I've just gotten my brand new 15'' macbook pro. When fully charged, it says that it can't last more than about 3 hours. Shouldn't it be around 7 hours?
What browser are you using? Firefox and Chrome suck a lot more juice with the discrete GPU than safari does.
Im doing the calibration now. When I charged it up to full, I happened to pull out the charger for a sec. Will that make a difference in calibration?1. Flash will kill it. Use safari and install Flashblock
2. Install GFXCardstatus and set it to integrated only.
3. Calibrate your battery.
4. Any video, games, etc. will kill your battery.
7 hours is attainable with Microsoft Office and basic web browsing with Safari w/ no flash at 50% brightness running Snow Leopard. That's how it is for me
Don't worry about it.
what browser do you use? Because if you use chrome, you're engaging the dedicated graphics card, which is probably what's killing your battery life. Try installing gfxCardStatus and setting it to integrated only.
Download coconut battery.
- check the capacity (should be close to 6900 mAh)
- check the power usage. If you are somewhere between 10-15 Watt, you should be in for 6-7 hours of battery life. If you're more between 25-30, you are looking at 3-4 hours max.
The sandy bridge quad cores are super fast, but very needy. Whenever you put load on your system, e.g. copying large files, compiling code, flash videos, it will start sucking your power.
Right now I'm on safari, keyboard light turned off, display 4 bars under full brightness, and using 10.2 Watt. Battery is 71% full and says 5:45 remaining.
Im over 30 atm. Why is that?
Edit: Wow. Literally just jumped too 34.3 watts.
What exactly are you doing atm? Check your activity monitor what's using the power.
Im watching a video on my external screen.
No wonder it's using a lot of power then.
If you're concerned about your battery, MBP batteries are very cheap. If you don't feel like replacing the machine altogether because you think it's a defect with your laptop, I would just buy a new battery, or see what's eating it up like that and decide if you need a new one.
It isn't really "unchanging" more than it was before i plugged it into the external screen really