45w charger instead of 85 is it ok?
I it ok to use a 45w charger on my 15" MBP?
MacBook Pro, OS X Mavericks (10.9.1)
in the reverse case, if you use too low a wattage adapter (e.g. 45W one on a MB Pro), there won't be enough current to charge the battery, although you can run it off AC power while plugged in.