MacBook Pro mid-2012 Battery Charging Issue

b4peace

macrumors member
Original poster
Aug 4, 2014
30
0
I just bought this refurbished mid-2012 LED MBP on eBay and after charging the battery to 100% (it arrived at about 34%) it started gradually losing charge over several days and stuck at 97%.

The mains charger showed a green light, no amber light.

The Power System Report said it was fully charged, but it wasn't.

The eBay seller told me to try an SMC and PRAM reset, which I did. Nothing changed that I could see. But, the next day I turned the MBP on and it started to charge - up to 100%, amber light on.

I thought it was fixed but since then the battery is now at 99% and not charging. This is what the Power System Report says today:

Charge Information:
Charge Remaining (mAh): 5502
Fully Charged: Yes
Charging: No
Full Charge Capacity (mAh): 5583
Health Information:
Cycle Count: 141
Condition: Normal
Battery Installed: Yes
Amperage (mA): 0
Voltage (mV): 12480

I've attached a screenshot of the Power System Report which says that it's fully charged (below max. capacity) and is not charging.

Any suggestions appreciated.
 

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athom1031

macrumors newbie
Oct 10, 2017
2
0
Your Macbook won't charge between 93% - 99% by design. No issue here unless there is something else you didnt state.
 

Fishrrman

macrumors P6
Feb 20, 2009
17,160
5,520
Run it until the battery is 50% discharged, then put it on the charger.
How far "upward" does it charge?

Use "Coconut Battery" (free).
Run it, take a screenshot of the results, post them here.
 

athom1031

macrumors newbie
Oct 10, 2017
2
0
Run it until the battery is 50% discharged, then put it on the charger.
How far "upward" does it charge?

Use "Coconut Battery" (free).
Run it, take a screenshot of the results, post them here.
Fishrrman, I'm pretty sure this user doesn't realize that his MacBook won't charge from 99% by design. If you look at the screenshot he posted, that is what any MacBook Pro would say. Do you see something else in this post that would indicate otherwise?
 

b4peace

macrumors member
Original poster
Aug 4, 2014
30
0
I just bought this refurbished mid-2012 LED MBP on eBay and after charging the battery to 100% (it arrived at about 34%) it started gradually losing charge over several days and stuck at 97%.

The mains charger showed a green light, no amber light.

The Power System Report said it was fully charged, but it wasn't.

The eBay seller told me to try an SMC and PRAM reset, which I did. Nothing changed that I could see. But, the next day I turned the MBP on and it started to charge - up to 100%, amber light on.

I thought it was fixed but since then the battery is now at 99% and not charging. This is what the Power System Report says today:

Charge Information:
Charge Remaining (mAh): 5502
Fully Charged: Yes
Charging: No
Full Charge Capacity (mAh): 5583
Health Information:
Cycle Count: 141
Condition: Normal
Battery Installed: Yes
Amperage (mA): 0
Voltage (mV): 12480

I've attached a screenshot of the Power System Report which says that it's fully charged (below max. capacity) and is not charging.

Any suggestions appreciated.


Thanks for the reply. The battery loses charge while plugged into the mains. Is that normal?

After the PRAM reset I was able to charge it up to 100% from about 95%. Now it's gradually losing charge again, currently down to 98%. I have only been using it plugged into the mains. It loses charge when not in use, after being shut down.

Sorry if I'm not explaining this well, but doing my best :)
[doublepost=1507817741][/doublepost]
Run it until the battery is 50% discharged, then put it on the charger.
How far "upward" does it charge?

Use "Coconut Battery" (free).
Run it, take a screenshot of the results, post them here.

Thanks for the suggestions, Fishrrman. I'll try them and post the results.

Coconut Battery test - screenshot attached.

Have yet to run the battery down to 50% - will do so and let you know what happens.

Thanks.
 

Attachments

Last edited:

Samuelsan2001

macrumors 604
Oct 24, 2013
7,682
2,103
Thanks for the reply. The battery loses charge while plugged into the mains. Is that normal?

After the PRAM reset I was able to charge it up to 100% from about 95%. Now it's gradually losing charge again, currently down to 98%. I have only been using it plugged into the mains. It loses charge when not in use, after being shut down.

Sorry if I'm not explaining this well, but doing my best :)
[doublepost=1507817741][/doublepost]


Thanks for the suggestions, Fishrrman. I'll try them and post the results.

Coconut Battery test - screenshot attached.

Have yet to run the battery down to 50% - will do so and let you know what happens.

Thanks.
Unless it has discharged to below 93% it will not charge back up again this is to protect you battery just don’t worry about it it is working normally we know what you mean this is just how they work.

Once it is charged to 100% it will not recharge back until it is below 93% again.

Take it off charge and see how it runs on battery check out how long it lasts etc and use it as a laptop. Then charge it back up and leave it on charge it will fluctuate between 93% and 100% as it slowly discharges to protect the battery while shutdown and runs off the mains when in use maintaining current charge while it runs on mains power.
 

b4peace

macrumors member
Original poster
Aug 4, 2014
30
0
Unless it has discharged to below 93% it will not charge back up again this is to protect you battery just don’t worry about it it is working normally we know what you mean this is just how they work.

Once it is charged to 100% it will not recharge back until it is below 93% again.

Take it off charge and see how it runs on battery check out how long it lasts etc and use it as a laptop. Then charge it back up and leave it on charge it will fluctuate between 93% and 100% as it slowly discharges to protect the battery while shutdown and runs off the mains when in use maintaining current charge while it runs on mains power.
Thanks for the explanation, Samuelsan2001. Greatly appreciated :) I'll run it as you suggest. Any idea how many hours it should run on a good, fully charged battery?
 

Samuelsan2001

macrumors 604
Oct 24, 2013
7,682
2,103
Well it’s five years old assuming it’s the original battery and it’s not too intensive use (internet streaming, documents etc) and you have screen brightness at 75% then I’d say about 5-6 hours for a 13 inch machine but it’s almost impossible to say really. They originally quoted 8hours on that machine if I remember correctly.
 

b4peace

macrumors member
Original poster
Aug 4, 2014
30
0
Thanks to every one who replied. Very helpful. FYI I let the laptop discharge to 50% and then charged it back up to 100% - no problem. All appears to be well ;)