The only problem I have ever had with it is one of the batteries sometimes doesn't want to take a charge. I get the fast red blinking light which means battery cold,hot or faulty. I normally let it sit or continue using it and then it charges fine. (I just charged both batteries and had no problems).

The only reason I'm selling is to upgrade to the newest Snap On gun (CT7850). The only advantages this gun has over the one I'm selling is it has 100 ft lbs more torque,has an led light,slightly smaller and weighs half pound less.
Hardly makes it worth it to upgrade with a $700 price tag.

Specs:
http://image.snapon.com/international/pdf/ct4850.pdf