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paulrbeers

macrumors 68040
Original poster
Dec 17, 2009
3,963
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I'm trying to find the definitive answer on this. I have an extra 60 watt MagSafe from my previous 13" 2009 MBP. I have two locations in my house I will use my MBP and would like to not have to haul around the power adapter. Can I use my extra 60 watt MagSafe instead of my 85 watt one? Even if this means using partial battery power to make up for the extra 25 watts I would be okay with it. Eventually I will buy another 85 watt one, but in the short run I'd like to use it.
 
Yes, you can use the 60W cord but don't be surprised if you see it say (Not Charging) next to the battery an awful lot. Hell I've had times where the 85W cord isn't enough to both run and charge my 17in Pro under certain heavy loads.
 
Last edited by a moderator:
It will work, just not very well.

The normal adapter is 85W, so you're missing out on 25W. Under load, the 2.3 15" will pull a peak 93.2W, which leaves even the 85 at a loss. What you will often see if you do any hard work is the 60W not charging your laptop, and sometimes the battery draining. Of course, if you don't do any hard work, and don't constantly use your laptop, it might not be an issue, but that's up to you.
 
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