Just got a new rMBP 13" and was setting it up. Instead of using the new charger that came with it, I already had a 85W Magsafe charger plugged in right there, and with the little Magsafe port adapter, I was charging the new MBP while setting it up. I noticed that the LED light on the tip never did come on, but the MBP showed it was charging. After about an hour, I thought I would try reversing the Magsafe connector to see if the light would come on. It was HOT. Not too hot to touch, but plenty hot. After fiddling with it a few time, I finally got the tip LED to light orange, but then thought I should just disconnect it and use the one that came with it. So my question is, should I be able to use these 85W chargers with a new rMBP 13? I have a few (all in like-new condition with perfect cords and connectors) and was hoping to be able to use these instead of having to buy new ones . Advice?