New rMBP 13 with older 85W Magsafe charger OK?

dmylrea

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Sep 27, 2005
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Just got a new rMBP 13" and was setting it up. Instead of using the new charger that came with it, I already had a 85W Magsafe charger plugged in right there, and with the little Magsafe port adapter, I was charging the new MBP while setting it up.

I noticed that the LED light on the tip never did come on, but the MBP showed it was charging. After about an hour, I thought I would try reversing the Magsafe connector to see if the light would come on. It was HOT. Not too hot to touch, but plenty hot. After fiddling with it a few time, I finally got the tip LED to light orange, but then thought I should just disconnect it and use the one that came with it.

So my question is, should I be able to use these 85W chargers with a new rMBP 13? I have a few (all in like-new condition with perfect cords and connectors) and was hoping to be able to use these instead of having to buy new ones .

Advice?
 

snaky69

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Mar 14, 2008
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It's fine. The battery decides how much juice to draw, not the other way around. You're not damaging anything.
 

dmylrea

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Sep 27, 2005
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It's fine. The battery decides how much juice to draw, not the other way around. You're not damaging anything.
Any ideas why the LED wasn't lit, but the Macbook battery indicator showed it was charging?
 

snaky69

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Mar 14, 2008
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Any ideas why the LED wasn't lit, but the Macbook battery indicator showed it was charging?
It happens once in a blue moon on all of the chargers I've owned. It has never affected anything so I don't worry about it.
 

dmylrea

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Sep 27, 2005
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Thanks all, I'll keep an eye on that one charger and try a couple of my other 85W chargers to see if they behave similarly.
 

Freyqq

macrumors 601
Dec 13, 2004
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Computer will draw up to the amount that the brick can handle, so it'll ask for exactly what it needs. It works fine.
 

dmylrea

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Sep 27, 2005
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Given the responses, I think I might have not worded the question clearly. I'm not concerned about using a 85W adapter when it calls for a 60W...I know the computer will only use what it needs. My question was more about the Magsafe adapter being extremely HOT while charging and the LED not being lit.
 

MacInTO

macrumors 65816
Apr 25, 2005
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Canada, eh!
I use 85w chargers with two different 13" MBPs. Sometimes on one of them, the green light turns off when the battery is fully charged, but the Mac states it is still plugged in. However, it was never hot.

One time when one of my chargers got really hot, it stopped working shortly after.