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sunlit

macrumors member
Original poster
Mar 5, 2011
51
12
I've been observing my new Macbook Pro 17", 2010, core i5 battery use, monitoring the amperage parameter in system profiler. After being fully charged, and the charger cable light turning green, I see amperage still showing around 600 mAh charge current, and it does not seem to ever stop, no matter how long I wait (some say trickle charge should stop after approx 2 hours).
Now, if I disconnect the charger, and then reconnect it again within a few seconds, and restart my mac, the system profiler shows charge as zero mAh, thus indicating that all charging has effectively stopped.
However, as I mentioned above, this does not happen if I keep the charger connected after fully charging the battery.
Is this behavior normal?
I have also observed that system profiler info sometimes stops updating (e.g. after I disconnect and swiftly reconnect the charger it is stuck at last reading, not updating after I hit Cmd+R), so it might be that it is just stuck on latest trickle charge figure, and not updating properly?
 
e.g. now I am well past 2 hours after the light turned green and battery reached 100% according to battery reading in the menu bar, and the profiler shows 632 mA, and (that's weird) coconut battery tells me my "battery power usage is 437.8 Watt"
after restart, or sleep-wake cycle, the charge current drops to zero, and stays there - so can anyone confirm that this is indeed the regular charge cycle - i.e. put discharged battery on charge, charge till 100%, and it stays on 600 mA trickle charge indefinitely, until rebooted, or restart, upon which the trickle charge stops? My original idea was that trickle charge should stop after some time, but in my case it is not so.
 
e.g. now I am well past 2 hours after the light turned green and battery reached 100% according to battery reading in the menu bar, and the profiler shows 632 mA, and (that's weird) coconut battery tells me my "battery power usage is 437.8 Watt"
after restart, or sleep-wake cycle, the charge current drops to zero, and stays there - so can anyone confirm that this is indeed the regular charge cycle - i.e. put discharged battery on charge, charge till 100%, and it stays on 600 mA trickle charge indefinitely, until rebooted, or restart, upon which the trickle charge stops? My original idea was that trickle charge should stop after some time, but in my case it is not so.

My 13" would charge to 100, stop charging and fall to 95% then charge to 100 again. I havent tested my 15" yet.
 
Your battery is designed to charge quickly until it gets to a high percentage, then charge more slowly after that until fully charged. It's also quite normal for it to stop charging somewhere between 93% and 99%, rather than charging to 100%. For details, read the link below. This should answer most, if not all, of your battery questions:
 
My 13" would charge to 100, stop charging and fall to 95% then charge to 100 again. I havent tested my 15" yet.

so can you please check with system profiler (right-click the apple sign, about this mac, more info), if after reaching 100% the amperage parameter continues to show small charge current. The important thing here is not to restart or sleep your macbook, just keep using it connected to mains, after battery reaches 100%.
 
e.g. now I am well past 2 hours after the light turned green and battery reached 100% according to battery reading in the menu bar, and the profiler shows 632 mA, and (that's weird) coconut battery tells me my "battery power usage is 437.8 Watt"
Have you reset the SMC?
 
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