battery life, macbook

[jbusc]

I have a white 2ghz macbook, bought it early august I guess..

I've been (loosely) tracking my battery life, both hours of usage as well as what coconutbattery reports..

For the first month and a half or so, I would have around 5250mAh to 5300mAh capacity ("original" capacity, 5200mAh)

Then, it dropped to about 5200mAh capacity after doing a monthly calibration, though the actual time the computer could operate actually went up, and held there a while.

Now, though, in the past 2-3 weeks or so the battery life has dropped significantly, from 5175mAh down to about 4900mAh, along with a marked drop in actual battery life (about 45 minutes to an hour less)

In recent days I have been busy at school draining it all the way until the battery indicator is red, then closing it up and recharging at home...this seems to contribute to the drop.

I would recalibrate, except the deep draining process seems to be the problem. Any ideas? Is a drop of 275mAh in a span of 2 weeks normal?

 

[erikamsterdam]

Don't know what is "normal", but 1 thing is good to know about modern batteries: they don't have a "memory" effect anymore like old NiCads. So draining and recharging does not revive your battery, just wears it out.
A normal Lion battery has a life of about 200 - 250 cycles of charging/discharging.
The discharging that Apple recommends is only to learn the OS the new (lower) capacity of the battery.

 

[elppa]

After a full charge mine is reading as 1:31 left, yet only a few months ago it was indicating 4-4 1/2 hours.

It's gone from a current capacity of 5253mAh (85 battery load cycles) on the 6th October, to a a current charge of 4943mAh today (89 battery load cycles) (26th October).

 

[matt311rocks]

I'm down to 3025 max capacity after 100 cycles and 6 months on my white MacBook. Sometimes a full charge will tell me ~1:30 sometimes close to two hours. I hope this is not normal. I will probablly be calling applecare soon...

Edit: I have done several battery calibrations and reset the PMU which helps little if none at all.

 

[jbusc]

mine is now 4849mAh (down from 4900mAh when I posted this, just yesterday)

I think that if it continues dropping at this rate, I will call applecare and see what they have to say.

(65 cycles and 4 months, if anyone is interested)

 

[rcpmac]

try resetting power managment

http://www.thexlab.com/faqs/resetpmchip.html#Anchor-Types-49575

 

[shakerbaby]

3 months 96 cycles and 4855mA

 

[elppa]

After a full charge - should the battery give you more than 1 hour 30 minutes?

- Full Brightness
- Bluetooth off
- Airport off

This is with a current capacity of 5005mAH (96% of original capacity (5200mAh)).

I was getting a good 3-4 hours before - it's really plummeted in the last few week.s

 

[Grakkle]

Same thing on my Macbook. Here's a screenshot of CoconutBattery:

http://att.macrumors.com/attachment.php?attachmentid=60732&stc=1&thumb=1&d=1161958147

It's a bit worrisome, since I've only had my Mac for about a month, and the battery only has 19 loadcycles on it.

 

[elppa]

It's £100 pounds for a new battery!

What on earth are you paying for...

A 13% drop in capacity means 2-3 hours drop in usage time.

That's absurd.

 

[trapperjohn117]

i keep mine plugged in most of the time but ive taken it for a couple of trips i still get around 2 1/2 hours a charge.