Is it safe to use an 85W PSU on 13.3" MBP

Jimathy

Jimathy

Jimathy

Associate
Joined
18 Oct 2002
Posts
894
Location
Sunny South Devon
Mistakenly bought a second 85W PSU for a 13.3" MBP which has a 60W one.

Is it safe to use it or should I leave it sealed and send it back?

Cheers.
 
The extra wattage alone won't damage your laptop

The wattage is simply a combination of the voltage and amperage of your PSU

More volts can kill your laptop, more amps won't make any difference at all

Say your standard 60W PSU has a voltage of 24V. This would mean a current of 2.5A (watts = volts*amps)

If your 85W PSU also has a voltage of 24V, this equates to a current of 3.33A. As the volts is the same but the current is higher it doesn't matter at all - it will work fine

If, however, your 85W PSU has a current of 2.5A but a voltage of 32V then don't use it as this could damage your laptop (the voltage is higher)

The other issue to check is the polarity of the connector which will be shown on the PSU itself

Basically, check each PSU. If the volts and polarity are the same then it will be safe to use
 
Unless this can be confirmed to work and work without issue, send it back mate. Why risk bricking your expensive MacBook Pro over a little bit of hassle?
 
I'm tempted to say it'll be fine.

Reasoning being;

When an 85w MBP is charging and being used it's using all 85 watts. When you haven't got enough power (eg airline adapter) it'll run it but not charge it.

Similarly on a desktop PC; if you're rig needs a 500w PSU and you put in a 800w PSU it won't suddenly blow up
 
If there were any danger then Apple would have made the connectors visually or physically different. There are going to be plenty of multi-MacBook homes/offices with mixed PSUs lying around.
 
Yup, don't worry about it. Was using my MBP charge on my MB for yonks as I'd borked the original in a sink (long story).
 
Of course it work just fine... Gee, why wouldn't it?! I fact it'll probably work better, won't get as hot as the 60W ones do.
 
You must log in or register to reply here.
Back
Top Bottom