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lauriita

macrumors newbie
Original poster
Feb 4, 2016
2
0
Hey people,
So I got a Macbook Pro ( late 2009 if it matters ) just got a brand new charger because the old one was sparking a bit and made my laptop shut down every time i plugged it in so obviously had issues.
Just plugged in my new one for the first time and I'm using Coconut battery which says it only charges with 34-45 watts instead of full 85w.
As I read from everywhere it is not good to charge with less watts..
Is there a way to find out if its a problem within the laptop or charger issue again.. or is it just the app thats wrong..

Any help appreciated :))
 

joe-h2o

macrumors 6502a
Jun 24, 2012
997
445
The Macbook Pro decides how many watts it is going to draw. This is totally normal. It will use more power when the battery is low and then gradually reduce the power when the battery is about 75% full, taking much longer to charge up the last bit. Charging too fast when it's nearly full can damage the battery.

Also, charging the battery at the highest power draw is about 40-45W. The other 15-20W "left over" is power that can be used to run the computer.
 
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simonsi

Contributor
Jan 3, 2014
4,851
735
Auckland
As I read from everywhere it is not good to charge with less watts..


Thats nonsense, the Mac charger is managed by the Mac (ie drawing less than the full wattage of the charger), all the time. Many users on here (me included), also interchange 85, 60 and 45W chargers with zero ill effect.
 

lauriita

macrumors newbie
Original poster
Feb 4, 2016
2
0

Thats nonsense, the Mac charger is managed by the Mac (ie drawing less than the full wattage of the charger), all the time. Many users on here (me included), also interchange 85, 60 and 45W chargers with zero ill effect.

I just meant when you google even Apple says you cant use a 40W charger for a laptop that originally comes with 60w or 85w one for example..
[doublepost=1454576271][/doublepost]I'm just worried since my last charger was sparking and shut down my computer if I couldve damaged the charging point or whatever its called and if there is a way to check
 

simonsi

Contributor
Jan 3, 2014
4,851
735
Auckland
The effect is as it is lower wattage under heavy load the MBP will draw from the battery as well as the charger, with a lower power charger it will obviously drain the battery faster under such heavy load - but that is the only implication. Much of the time even the 85W charger is providing 5W or less to maintain the battery.

You can use any charger, if you <couldn't> then Apple would have had to provide different connectors for each charger size to prevent cross-usage.
 
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