Howdy All

today at uni I noticed that my battery life dropped significantly and that my battery health dropped from 99% down to 87%.

So I thought I'd see how everyone else rates the battery life of their macbooks/macbook pros.

Also any ideas as to why the battery life would suddenly decrease so dramatically. I only just last week calibrated the battery.

I suppose it would help if people posted how old their macbook/pro is and what they use it for. i.e. pro apps, basic word processing etc

theov

UPDATE:

I am now consistently getting only 2 hours battery life with airport/bluetooth both off and the brightness turned right down running only preview & word. Could this mean my battery is stuffed and replaceable under warranty?

My MacBook Pro battery is rock solid, I get around 3:30-4:00 hours out of consistently.

My MacBook did exactly that, dropped from about 98% to 87% overnight. A week later the battery completely died (atleast it didn't spontaneously ignite!). I got it replaced under warranty without a problem.

I can get around 4 and a half hours with WiFi on if I try hard enough, although generally I get just under 4 hours as I set the screen brightness to around medium and have a number of apps running (Office, Firefox, iTunes, Adium etc).

Download an app called CoconutBattery, which should return some info about your battery.

Cool little app except that it tells me that my computer is 24437 months old!!

Somehow I think that could be a little off



Also I was consistently getting 4 hours of battery life with brightness below half and wifi off just using Word and Preview (to view lecture slides) and when I got to uni today it only had something like 2.5hours at 99% charge!!

theov

Some battery life issues are because of battery 'memory'. Yep, I realise Li-Ion don't suffer from this 'memory effect' - but apparently macs do!
The problem seems to be many cycles of allowing the mac to run down to about 25%, recharging incompletely, then repeating (or similar) makes the mac get confused about where the upper and lower limits of battery life lie - basically, it gets out of calibration.

There's a simple way to recalibrate your battery which i'm not 100% sure of. Basically I think you just drain the battery till the mac shuts down, recharge it to full, use it for 30 mins or so with the power connected, then disconnect the battery and repeat by running it down until it shuts down - then repeat one or more times.

Someone else can probably clarify this, but personally I always try to recharge only when my mac reaches a very low battery life, and I try to leave it charging until it's full. I will do this charge-cycling thing soon though.

- Jeremy

Recalibrating needs you to leave the battery in it's discharged state for at least 5 hours before recharging according to Apple.

Oh and my battery is fine but it does get stuck showing "charged" even when it's been on battery for 3 hours. A restart fixes it.

Im the same with decrypt. My MBP battery is great!

Can't complain.

I made it last over 5 hours once. That was when iI forgot my charger and went on holiday for a week!

When I first got it I remember being very excited that I actually got very close to 6 hours battery life out of it!

However I'm thinking I may be suffering the same problem as Repulse as having just checked it again the health is now down to 84%.

theov

According to apple this is how to calibrate Macbook/Pro batteries.

theov

I remember reading somewhere that if the battery capacity drops lower than I think 80% within the first year, then your battery is eligible for a free replacement. I'm not sure whether this is true or not - you'd have to ask Apple or a Mac reseller.

How many charge cycles have you gone through?

Repulse, I don't know Apple's policy outside of North America & EU but generally the battery is covered for 6 months(no matter if you paid extra for extended AppleCare) unless you've reported the issue several times in that period and have several case #s to reference as proof. There are ways around the 6 month factor in the EU due to pro-consumer laws but I wouldn't want to be quoted on that as it could change - AppleCare always limited their replacement liability on batteries(its referenced as a consumable item).

From personal experience with PowerBooks and friends with iBooks & MacBooks, if you do more deep drains(full drains to sleep or ~10-15% battery remaining) the battery will easily be down to about 80% capacity within a year. On the other hand *knocks on wooden desk*, the fewer deep drains, you can usually look foward to about 10-15% drop for the first two years and then it seriously degrades from there.(I'm going by past Alu-era PBs I've had or used).

*sigh* I'll find out my battery stats on a MacBook soon... planning to buy one in a couple of weeks.

Slightly off topic, but my nearly six year old ibook 500's battery was completely dead after about 2 years. It wouldn't even stay asleep for more than 2 days without completely turning off.Seeing as I mainly use it on mains, this did not bother me. Just the other day hwoever, I had it plugged in for about a weekend, following which I was able to run it doing MYOB (as if you can do anything more intensive on this machine) for 1 hr without mains. Talk about a second wind..... Hold onto those old batteries, there is hope yet !!!

53 charge cycles. Though few of them have been deep/full cycles.

theov

UPDATE:

I am now consistently getting only 2 hours battery life with airport/bluetooth both off and the brightness turned right down running only preview & word. Could this mean my battery is stuffed and replaceable under warranty?

theov