Macbook - battery confusion

idPlease

Hi.

I've a macbook and had it nearly a year now, would use it every day for a couple of hours easily.

In the past couple of weeks i've noticed a drop in the length of time the battery lasts for (when off the mains).

I've always had the battery set to 'better battery life" and mostly charge it up fully.

yet recently, i've noticed the battery goes after about two hours (if i'm lucky) and the remaining time option when i click on the battery icon is very unreliable. I can click on it one minute and it will read 2hrs 35 mins remaining the next minute it shows up saying i've 50mins left!!! :eek:

I calibrated it this weekend for the first time and i'm not sure if it has worked. How long should the battery last for? I mostly use the macbook for internet surfing, project work and listening to music.

Also forgot to mention, i calibrated it on friday night by charging up fully, leaving plugged in for 2hours, then run battery down, let it sleep (did so as battery was at 0%), left for over 5hours, then charged next morning. When i plugged in power cable it showed battery was at 52%!!

Type 17

Steps to take:

Install iStat Pro Widget - shows battery health, as well as percent charged and it's free. I'd also recommend Coconut Battery

Set your power options to always on, never sleep, etc and then:

Calibrate your battery according to this article a number of times - I've recovered batteries that were below 70% health back to 100% by calibrating five or six times.

idPlease

Thanks a mill for the advice.

What will come off turning off sleep etc?? I thought that saved the battery, no?

Do i have to calibrate it 5/6 times in a row to get back that level of battery power??

Edit: have downloaded iStat which looks great
the vitals are as follows:
Health - 95%
Cycles - 224
Charge 90%

Thats pretty good right?!

Type 17

Turning off sleep is only for helping the batt run down faster - you can switch things back afterwards.

When you've installed an app/widget that shows your battery's health, you can repeat the calibration process until you get to (or near) 100%. It could get there in two goes, or it could take more - keep doing it until it's not making a difference or it's back to 100%, whichever comes first.

Type 17

idPlease wrote: »

Edit: have downloaded iStat which looks great
the vitals are as follows:
Health - 95%
Cycles - 224
Charge 90%

Thats pretty good right?!

95% is pretty good, as you say, but run one or two calibrations and you should get it back to 100%, and you will extend the life of the battery the most by keeping its health at 100% for as long as you can, by running a calibration cycle about once a month.

idPlease

Type 17, i've been surfing net since i last posted and the health has dropped dramatically to 52%!

i presume its a case of doing more calibrations to make the battery go as close to 100% for a longer period. As it only dropped to the current health of 52% when the battery reached around 70%...

I'm positive though as far as i'm concerned this is the first calibration i've done since i got the mac a year ago!

Type 17

idPlease wrote: »

Type 17, i've been surfing net since i last posted and the health has dropped dramatically to 52%!

i presume its a case of doing more calibrations to make the battery go as close to 100% for a longer period. As it only dropped to the current health of 52% when the battery reached around 70%...

I'm positive though as far as i'm concerned this is the first calibration i've done since i got the mac a year ago!

Do a few calibrations and see how you get on, the calibration does two things - it exercises the battery (think of the battery as a muscle, which becomes unfit unless exercised) and it calibrates the battery's actual condition against what the Mac OS thinks it is, so the readings in the menubar and iStat Pro will be accurate.

The fact that your health reading changed so much means that you probably need to do some more calibrations to see what the real story is.

Don't forget to leave the Mac asleep for at least 5 hours like it says in the article - this is important, as you won't get the right calibration otherwise.

idPlease

cool thanks for the advice, will do it again this week so.

leave it to sleep or once its dead turn the power off? because i left it sleep last time and when i plugged in the power adapter it showed 52% in the bar

Type 17

Leave it to sleep for 5 hours or more (overnight is good) - the battery keeps a bit back when it goes to sleep by itself, so you need to leave it for 5 hours or more to really run it down to zero.

I wouldn't worry about the 52% reading, given that it was 95% before, things may well be in a heap until you do a few more calibration cycles.

To give you an idea of how these things work, last year I recovered an old iBook G3 (new around 2000) which my brother had used (on its second battery) for over four years without calibration, which was down to around 70%.

Here's what I did:

1. Turned off all sleep (left display sleep on to protect old display).
2. Plugged out power, left it on until it had slept, and until the sleep light had gone out.
3. Plugged it in, woke it up, left it charging until 100% charged
4. repeated 2 & 3 until battery health showed 100% in iStat Pro. It took about four cycles of 2 & 3, which took three or four days.

I've also managed to keep my wife's MB (157 batt cycles, 26 months old) and my MBP (109 batt cycles, 18 months old) at 100% through regular calibration.