MacBook Pro Power Problems.

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Level 1

5 points

MacBook Pro Power Problems.

My MacBook Pro is exhibiting power problems. I am running Yosemite and it seems that the problem may have arisen since I dowloaded this upgrade. When the battery is charged it shows 99% charge and I can use it on battery power. As normal with use the charge gradually reduces, say to 30%. I then switch off using either the on/off button/apple logo, waiting for the dialogue box, " do you want to switch off etc". The next day, I switch on, but the computer will only boot up when the power lead is attached. When the computer comes on, usually as normal, the charge always shows 0%. When it is recharged the whole process repeats itself. Help please.

MacBook Pro, Mac OS X (10.6.8)

Posted on Mar 2, 2015 9:05 AM

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Answer 1

my ginger

Level 5

4,904 points

Mar 2, 2015 9:21 AM in response to rcoo26

Hi. What year MBP do you have? Have you replaced the battery recently? If you hold down the option key while click on the battery icon, it will give battery condition. Does the mag safe connecter light show just green or does it go to orange? Go to the apple,top left, about this mac/ systems/ power and check the charge rate/cycle count/ charge remaining/ and charge capacity. You could try a SMC reset and see if this helps.https://support.apple.com/en-us/HT201295

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Answer 2

rcoo26 Author

Level 1

5 points

Mar 3, 2015 3:46 AM in response to my ginger

Hi,

Thanks for responding. My MBP is late 2009 and the battery has never been replaced. When I look at battery condition, it registers as normal, as it does when I do the power checks you suggested. When I plug in the power cord it glows green and within a few seconds it is on amber, until fully charged. I've done the SMC reset. I noticed this morning that after using it last night the battery capacity was 93% and an expected duration of about 5.5 hours was listed. After limited use this morning, restricted to email admin only, the charge level had dropped to 88%, but the predicted duration was only 2.75 hours. Currently the level is 73% and the duration is 3 hours, although I have accessed the web several times. Presumably there is some sort of algorithm that looks at current usage and predicts the duration. I will continue to monitor this to see what happens. In the meantime if you have any more thoughts!!!

Regards

Roger

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Answer 3

rcoo26 Author

Level 1

5 points

Mar 3, 2015 8:56 AM in response to my ginger

A bit more. I switched off the computer before lunch with about 40% battery life and a predicted time to zero of 2.5 hours. I switched on about three hours later and the initial screen came up (not as far as log in) and then went dead. I could not switch on until I connected the power cord and the battery showed 0%. This is a common occurence.

Regards

Roger

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Answer 4

my ginger

Level 5

4,904 points

Mar 3, 2015 9:19 AM in response to rcoo26

Off the top of my head,I would say the battery needs to be replaced. It seems as if the info that the battery gives to systems is not accurate. I run 10.6.8 and in about this mac, more info,power. I get full charge capacity in mAh. Which is the capacity new. Then there will be charge remaining in mHa. Which is the most it has in it's current state. Cycle count is the amount of charge cycles it has gone through. Apple states 1000 cycles is the average life. More or less, depending on the battery and use. It is possible that when you are seeing a percentage and an hours left that in reality it's lest than that. Seeing that at 40% you have trouble starting and running. There could be a dead cell that is causing this ,but not being detected.

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Answer 5

rcoo26 Author

Level 1

5 points

Mar 7, 2015 7:41 AM in response to my ginger

Hi,

You are right, the battery is terminally ill. It will be replaced this week.

Regards

Roger

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