Macbook battery

Hello,
something really weird happened to my Macbook Unibody (nov. 2009). I don't know if it's due to the very hot weather in France, but the plastic under my Macbook just produced a bubble... (here is an image[/img] of what it should be, the bubble is on the right, near the USB ports)
So well I was kinda surprised... I'm using my Macbook everyday, and this day was a particularly hot one. I guess it helped...
But today, I started to be suspicious when I saw a warning, "Check your battery", near the battery indicator. I couldn't find any information about this...
So I downloaded Coconut Battery, that's a cool software btw, and here is what it says:


So first it said that my capacity is 78%. It looks normal from what I read on the Internet, that is, near 600 cycles, the battery starts to lack performances. My Macbook is 1,5 years old, has 542 charging cycles, so I guess it's normal...

But I have 2 questions:
- when should I change the battery ? At 50% ? Will it decrease slowly ? Or will it just go down, one day, to 10% when it's dead ?
- this morning it was 78%, this afternoon I launched a game, and it went down to 74% (see the screenshot), then I closed the game and it went back to 78%. Is that normal ? Does playing games affects my battery ?

Well if anyone knows, thanks in advance for helping me !

Cheers from Paris ! ;D

If you do a couple of searches, you'll find a lot of threads with the same question asked. However, yes, as you stated, the battery capacity will slowly decrease overtime, depending on how well you treat your battery. Personally *checks* I have 594 cycles on mine and 88.8 percent health.

What you can do is calibrate your battery, that will give you more accurate reads on the health of the battery. Now if there's bubbling, it is probably due to the heat. If you don't have a program or something that tells you the internal temperature of the machine, you should definitely get one. iStat and MenuMeters are great programs.

It is normal for the health percentage to fluctuate within 5 points though. If it goes from 70 to 50 and back again in the course of a few day you should definitely calibrate it though.

You have ALOT of load cycles on that battery, and about this "bubble" i couldnt see the pic... I think your battery is bad.

powerbook_guru said:

You have ALOT of load cycles on that battery, and about this "bubble" i couldnt see the pic... I think your battery is bad.

Click to expand...

Yea I know right? It's second hand too; I don't know how the guy did it but I guess I just got lucky.

Thanks for the tips, I'll download one of those programs.

The bubble is getting smaller now, but anyway I guess it was due to the heat and the fact that the computer was running all day long.

I did calibrate my machine, I followed the steps given by Apple, but it didn't change the percentages. I'll try to calibrate again, to see if there's any change.

Thanks for the answers

Paradoox said:

Thanks for the tips, I'll download one of those programs.

The bubble is getting smaller now, but anyway I guess it was due to the heat and the fact that the computer was running all day long.

I did calibrate my machine, I followed the steps given by Apple, but it didn't change the percentages. I'll try to calibrate again, to see if there's any change.

Thanks for the answers

Click to expand...

Well that's good; but there's no guarantee that calibrating changes anything in terms of numbers. All it does is give you a better estimate of the health of your battery and, as a result, more accurate percentage and battery life left.

A lot of people calibrate once a month. You should definitely calibrate when you insert a new battery as well. For the past few times I used the spare it would randomly cut off on me; I first attributed it to the battery being bad but a month before that it worked flawlessly. I think the computer just thinks the battery is dead (since I'm inserting the new one after the old is almost gone) and requires the charger.