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bigmat1201

macrumors member
Original poster
Apr 21, 2008
65
0
Houston
I just got my new macbook pro today :D, and I was wondering, would there be any problems using the smaller 60 watt power adapter with the MBP (instead of the 85 watt), I plugged it in and it works? The reason I ask is I've already got two 60-watt adapters from my old macbook, and I really didn't want to have to buy another one. I was told it might not charge the battery as fast, but I don't mind that, along as its not going to do any permanent harm (blow up the battery). Any advise. Thanks
 
You can typically use those to power it, but not charge it. So it can be a spare to RUN the system if you forgot your charger, that's all.

I'd instead ebay them and buy an 85W spare.
 
Yes, the 60 watt won't charge it. IT COMES WITH ONE.

He is talking about using a 60 Watt with a Macbook Pro which comes with the 85 Watt charger.

The 60 Watt will still provide power but it wont charge while the notebook is in use. It may charge it while it is off though.
 
It will charge it with it running. Not as fast as the 85w but it will charge. I use to use my friends from his Macbook on my 17" Santa Rosa at least once a week when I'd forgot to toss mine in my bag for my night classes.
 
Well, I've decided using the smaller adapter might work in a pinch, but it shouldn't be used all the time, I think it screws up the time on how long it take to charge the battery totally, ex. I'm at 85% charge right now and it says its going to take an hour and 51 minutes to completely charge the battery. I know my old MB didn't take that long when it was at 85%, unless MBP battery's just take longer to charge, does it really take 1:51 to charge totally at 85%? Also, someone told me that if you where doing something heavy duty on your MBP, and you were using the smaller charger, you might be using more power than the adapter can produce, and end up slowly draining your battery even though your plugged in, this makes sense, So it looks like I'm out another 85 bucks :(
 
Well, I've decided using the smaller adapter might work in a pinch, but it shouldn't be used all the time, I think it screws up the time on how long it take to charge the battery totally, ex. I'm at 85% charge right now and it says its going to take an hour and 51 minutes to completely charge the battery. I know my old MB didn't take that long when it was at 85%, unless MBP battery's just take longer to charge, does it really take 1:51 to charge totally at 85%? Also, someone told me that if you where doing something heavy duty on your MBP, and you were using the smaller charger, you might be using more power than the adapter can produce, and end up slowly draining your battery even though your plugged in, this makes sense, So it looks like I'm out another 85 bucks :(

I think it comes down to this... how much is your mac worth? Most of these power supplies and charging systems are very well designed and can tolerate a lot of, well, abuse.

However, there is always a reason why Apple states that the 85W is for a specific model vs. using a 60W. Sure, it might work, but you are going to be pushing it well beyond it's rated capability. Once you go beyond specs you might start to have overheating in either the power supply, or in the charger as it has to pull more amps at a lower voltage if power supply can't handle it...

Might work short term. I wouldn't take the risk long term.
 
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