MBP: Battery cannot reach 100%

[brandon.mat]

I'm not sure if this is due to the new battery firmware upgrade considering it happened acouple weeks after, but anywyas my battery could not reach past 99%, now it will not go above 98%, even though it is clearly fully charged, as I have not had it unplugged for a while (I use it as a desktop replacement for the time being). I tried removing the battery and reinserting, any suggestions would be appreciated. Thanks,

- Brandon.

[CPressland]

Try unplugging the power and leave the battery to fully discharge, probably take a few hours. Make sure the MacBook dosnt go to sleep and use it alot if you want to discharge it quicker.

Then Fully charge it up again.

[brandon.mat]

thanks, I'll give that a try now, is it bad to have it always plugged in?

[Not Cool]

As far as I know, it's better to leave it plugged in all of the time. Otherwise the battery loses life quicker over time. The only minor thing is that sometimes, like you just had, is that the battery meter doesn't register 100% so you have to drain it.

[mrelusive978]

As far as I know, it's better to leave it plugged in all of the time. Otherwise the battery loses life quicker over time. The only minor thing is that sometimes, like you just had, is that the battery meter doesn't register 100% so you have to drain it.

I can tell you from experience that this is false.

My ex wife leaves her iBook plugged in constantly, and within a year and a half, the battery would no longer hold a charge at all.

I, however, would drain the battery on a fairly regular basis in Uni, and charge it overnight...battery still has 88% of its original capacity after 3 years.

A good app is Battery Health Monitor, it will tell you all the info you need to know about your battery, including its current charging capability vs. the original charge capacity.

Overall, I would say it's very BAD to leave it plugged in all the time...I would say that, from my experience, that if you are going to do that, you should charge the battery and then remove it and just run the laptop from straight AC power till you need to go portable.

See Wikipedia's article on LI-Ion batteries for more info.

[KeR]

The one thing that kills the battery more than anything else is heat. Anyhow there is a article on Apple.com, too lazy to look for it now that states its normal for the battery meter to be anywhere between 95% - 100% when fully charged.

[SnowRanger13]

It really depends on the exact type of battery of how often it should be charged and discharged. On my Powerbook G4 I fully discharge the battery about once a month, my battery life is near when I bought it.

[mrelusive978]

It really depends on the exact type of battery of how often it should be charged and discharged. On my Powerbook G4 I fully discharge the battery about once a month, my battery life is near when I bought it.

That was the point I was trying to make...the problem is I think there is a decent amount of confusion amongst end users that are confusing how you used to have to take care of old NI-CAD laptop batteries (see, oh, Powerbook 1400) vs. LI-Ion batteries, its why I posted the Wikipedia article. But yes, I agree, the occasional total discharge is good for the life of the LI-Ion batteries, I'm sure that's the reason mine is still going strong at 4 hours of life.

[brandon.mat]

So I think I will fully drain the battery every other week or so to keep it up to cycle. I still have over 100% total battery life according to coconut battery, and i've had the laptop for about 3 months now.

[shadowmatt]

resetting pram etc... works, its more of a software thing I think

[mrelusive978]

resetting pram etc... works, its more of a software thing I think

I cannot recall the file, I will contact Applecare today since they need to send me replacement OS DVD's for my Mac Pro, but there IS a hidden system file that contains the settings for the PMU (power managment unit) on Apple's laptops...sometimes, trashing this file will fix a lot of power issues.

[shadowmatt]

I cannot recall the file, I will contact Applecare today since they need to send me replacement OS DVD's for my Mac Pro, but there IS a hidden system file that contains the settings for the PMU (power managment unit) on Apple's laptops...sometimes, trashing this file will fix a lot of power issues.

I have found that in the past letting the battery run down, booting with power and holding the kay combination in boot up resets the PRAM etc... and then the batery is recalibrated. Something along those lines anyway... Only needed to do it a couple of times.

[mrelusive978]

I have found that in the past letting the battery run down, booting with power and holding the kay combination in boot up resets the PRAM etc... and then the batery is recalibrated. Something along those lines anyway... Only needed to do it a couple of times.

There is that, which works well, as well as PMU reset sequences at bootup. They are different for each laptop, but the methods for each one can be found in this helpful link at support.apple.com.

[misecia]

apple have released a patch for anyone having battery problems on macbook and macbook pro's you might want to try that

[mrelusive978]

apple have released a patch for anyone having battery problems on macbook and macbook pro's you might want to try that

Actually, I went to the Apple Store to have them reinstall my OS (DVD's that came with the Mac Pro were actually defective...) and there were about 20 people there that had similar issues, and each one was resolved with the patch.

[Chad]

From the horses mouth...

Standard Maintenance

For proper maintenance of a lithium-based battery, it?s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month. Need a reminder? Add an event to your desktop?s iCal Source

[brandon.mat]

Thank's guys, basically I completely ran down my battery and recharged yet its only at 99% still. My battery health is well over 100% though, so I guess it might just be a software issue. As for the patch, I installed it the day it came in. Thanks for all your help though :) Now to figure out why startup takes forever...hmm.