What's the difference between a 85W MagSafe, a 60W and a 45W one?

DavidChavez

macrumors member
Original poster
Nov 10, 2009
60
0
Mexico
I know these chargers are for (in order) MacBook Pro, MacBook and MacBook Air.
Now I'm planning to buy a new one to replace my old broken Magsafe, that worked for my late 2007 white MacBook.
I found some sellers on the Internet only have a 85w at really good prices, but I wonder if a 85W will work well on my MacBook.

So, what's the difference between a MacBook Pro 85W charger, a 60W MacBook charger or a 45W MacBook Air charger? Will they work on any other Macbooks?
 

TEG

macrumors 604
Jan 21, 2002
6,573
51
Langley, Washington
They will all work with each other. If you use one that has more wattage than your machine requires, it may just work at the lower wattage, or it may be able to charge your battery faster (depending if there are fast-charge circuits in the machines). If you use one of a lower wattage than you need, it will charge your computer slower, and if you are doing anything major on your machine, you may not charge at all.

Get the 85W, it will work just fine.

TEG
 

CylonGlitch

macrumors 68030
Jul 7, 2009
2,932
129
SoCal
General rule for power supplies, you can not have too much power. In this case, the 85W supply will work fine to power/charge the 60W and 45W machines. The opposite is not true. Putting a 45 or 60W supply on a machine that needs to draw 85w can cause the machine to either not power up, not charge, or worse. I can cause the power supply to over heat and become a fire hazard.

So if 85W is, overall more useful, why have 60 and 45W supplies? Easy, they are cheaper to manufacture. So why supply a machine that only needs 45W a power supply of 85W if there is a significant price delta. You don't, you save the few dollars.
 
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chadvonnau

macrumors newbie
Apr 12, 2008
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CylonGlitch is right.

Though be careful telling this information to non-technical users. There's a reason Apple only recommends using the power adapter that the system came with. You can't screw anything up that way.
 

ActionableMango

macrumors G3
Sep 21, 2010
9,514
6,772
They are also different sizes and weight. I have 85w and 60w power supplies from the original MacBook Pro and MacBook. The 85w is physically bigger and heavier.

So if you have to lug a power supply around, I'd get exactly the one that goes with your laptop and not get the larger one.
 

cmd311

macrumors newbie
Mar 7, 2013
1
0
Dimensions of MacBook Power Adapters 85W, 60W, and 45W

MacBook Power adapter weight and dimensions:

Watts...Weight g (oz).......L x H x W (mm)

..85.......309 (10.9)........79 x 79 x 29
..60.......255 ( 9.0).........74 x 74 x 29
..45.......172 ( 6.1).........64 x 64 x 27

(Note: The 45W adapter was measured at home from a 2011 MBA with the "L" type MagSafe WITHOUT the attached 3-pronged cord. Aside: the 6 foot 3-pronged cord weighs 138 g. The data on the 85W and 60W adapters was gleaned from various internet sources with the ASSUMPTION that the weights are without the 3-pronged cord.)

Addendum: The 45W power adapter WILL recharge an actively processing Late 2008 MacBook with 2.4GHz Intel Core 2 Duo processor modified with an SSD hard drive. though at a slightly slower rate than the recommended 60W adapter. (Sorry, I have not measured the charging times of each, though observed "guesstimate" is that the 45W adapter is 50 - 75% slower than the 60W adapter).
 
Last edited:

paulrbeers

macrumors 68040
Dec 17, 2009
3,961
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So, what's the difference between a MacBook Pro 85W charger, a 60W MacBook charger or a 45W MacBook Air charger? Will they work on any other Macbooks?
I have had mac laptops that have used all three wattages. I always buy the 85w ones as my back up. Why? Because the 85w will work on any laptop, but the 45 and 60 will not (or at least will have very reduced experience). Further, the cost difference between the 45, 60 and 85 is virtually nothing so you might as well "go big" and never worry if you have the right adapter for the right laptop.
 

flynz4

macrumors 68040
Aug 9, 2009
3,131
37
Portland, OR
They are also different sizes and weight. I have 85w and 60w power supplies from the original MacBook Pro and MacBook. The 85w is physically bigger and heavier.

So if you have to lug a power supply around, I'd get exactly the one that goes with your laptop and not get the larger one.
I agree. I had 5 of the 85W adapters back when we had two MBPs. About 3 - 4 years ago we switched to MBAs, and we are never planning to go back to heavier laptops.

We used the newer 45W chargers for travel... and the older 85W chargers were left in fixed locations such as desktops. Over time, as we have been replacing older monitors with TBDs... the 85W chargers have been relegated to "junk drawers". I still don't want to throw them away... but the are just not being used anymore.

/Jim
 
Nov 28, 2010
22,670
28
located
MacBook Power adapter weight and dimensions:

Watts...Weight g (oz).......L x H x W (mm)

..85.......309 (10.9)........79 x 79 x 29
..60.......255 ( 9.0).........74 x 74 x 29
..45.......172 ( 6.1).........64 x 64 x 27

(Note: The 45W adapter was measured at home from a 2011 MBA with the "L" type MagSafe WITHOUT the attached 3-pronged cord. Aside: the 6 foot 3-pronged cord weighs 138 g. The data on the 85W and 60W adapters was gleaned from various internet sources with the ASSUMPTION that the weights are without the 3-pronged cord.)

Addendum: The 45W power adapter WILL recharge an actively processing Late 2008 MacBook with 2.4GHz Intel Core 2 Duo processor modified with an SSD hard drive. though at a slightly slower rate than the recommended 60W adapter. (Sorry, I have not measured the charging times of each, though observed "guesstimate" is that the 45W adapter is 50 - 75% slower than the 60W adapter).
And for that you registered here and revived a more than two year old thread?
 
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GWIM2

macrumors member
Sep 21, 2011
56
4
Scotland
I needed the answer ...

... to exactly the same question, almost, so thanks for reviving it. :)

My old spare MBA 45w has given up, I have a new one for portable use, but want another for fixed home use.

A new 45w here is £60 ( pushing US$ 100 ) but I can get new genuine 60w units from E-Pay for £31 ( maybe US$ 50 ) including delivery, so guess which one I'm going to buy ?

Gordon
 

sweet coco

macrumors newbie
Oct 12, 2015
1
0
I know these chargers are for (in order) MacBook Pro, MacBook and MacBook Air.
Now I'm planning to buy a new one to replace my old broken Magsafe, that worked for my late 2007 white MacBook.
I found some sellers on the Internet only have a 85w at really good prices, but I wonder if a 85W will work well on my MacBook.

So, what's the difference between a MacBook Pro 85W charger, a 60W MacBook charger or a 45W MacBook Air charger? Will they work on any other Macbooks?
To find the right charger for Macbook ,there are three kinds of power rating Macbook power adapter in the market,45 watt, 60 watt, or 85 watt. It should be noted that higher wattage chargers can be used on the lower wattage laptops, but not vice versa.For example,If you have mac laptops that have used all three wattages. you could buy the 85w ones as my back up. Why? Because the 85w will work on any laptop, but the 45 and 60 will not. Further, the cost difference between the 45w, 60w and 85w is virtually nothing so you might as well “go big” and never worry if you have the right adapter for the right laptop.You can also find the Power Rating details on your orignal macbook charger and get the same Power Rating as your origanl macbook charger .
This guide maybe can help you.
http://www.eachbattery.com/guide/how-to-choose-the-right-macbook-charger/
 

Titi29

macrumors newbie
Oct 13, 2015
2
0
image.jpg image.jpg
image.jpg
which right adapter suitable for this macbook?can you recommend the right adapter
For this macbook or picture it will be helpful
 
Last edited:

Fishrrman

macrumors Core
Feb 20, 2009
19,478
6,768
Titi wrote:
"which right adapter suitable for this macbook?can you recommend the right adapter
For this macbook or picture it will be helpful"


Looks like a 60w is what you need...
 

Titi29

macrumors newbie
Oct 13, 2015
2
0
Titi wrote:
"which right adapter suitable for this macbook?can you recommend the right adapter
For this macbook or picture it will be helpful"


Looks like a 60w is what you need...
Really?can you send me a picture?
 
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