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sweetstyle

macrumors newbie
Original poster
Jan 30, 2013
15
2
Does leaving a MacBook Pro permanently connected to a power supply damage the battery and reduce its life? Or is the equipment smart enough to prevent this?
 
Does leaving a MacBook Pro permanently connected to a power supply damage the battery and reduce its life? Or is the equipment smart enough to prevent this?

The power supply is just that, a supply. The computer knows how much juice to take in.
 
No it will not damage it. If battery full then the system stops charging and just runs off tap power.
 
No, but leaving the power supply plugged in when you're not using it will shorten its life; if its generating heat, its working hard for no benefit.
 
No, but leaving the power supply plugged in when you're not using it will shorten its life; if its generating heat, its working hard for no benefit.

It won't shorten it's life much. All you need to do is use it from battery once every few weeks. Heat will always shorten its life a little whether it's plugged in or not.
 
Does leaving a MacBook Pro permanently connected to a power supply damage the battery and reduce its life? Or is the equipment smart enough to prevent this?

Permanently?

If, by "permanently," you mean leaving it connected to its power supply for the next three years, never unplugging your brand new computer until you decide to sell it? Yes, it will most likely damage your battery.

If, by "permanently," you mean using it connected to your power supply more often than not, unplugging it once every few weeks or so? No, you will not damage your battery.
 
It won't shorten it's life much. All you need to do is use it from battery once every few weeks. Heat will always shorten its life a little whether it's plugged in or not.

If its always plugged in, it won't last as long, but whether that matters will depend on how long you intend to keep it. I'm not suggesting that they shouldn't be plugged in for powering the 'book, only that they be unplugged when aren't being used for charging or powering the 'book.

They're a lot hotter when they're plugged in than when they aren't, and how long one will last is a crapshoot; they do die, and they are rather expensive to replace.
 
There is the Theory and there is practice. My Macbook pro was plugged in 95 percent of the time after I got an Ipad because it rarely if ever moved from my desk. After 12 months of doing this I had at most 30 minutes battery life available when I tried to use it disconnected.


I just bought a new battery and believe me I will be treating it very differently this time around.
 
Been running mine for over 3 years with power supply plugged in most of the time. Battery is still good.
 
Thanks for all the replies, you've been most helpful...

let me be the first "Merry Christmas"
 
Does leaving a MacBook Pro permanently connected to a power supply damage the battery and reduce its life? Or is the equipment smart enough to prevent this?

No it will not damage the battery by leaving it plugged into the AC adapter. But if you aren't at least taking the battery down to below 5% once a month it will definitely decrease the battery life.
 
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