Using 45W Power Adapter with MacBook Pro Retina 15 I would like to know if I am able to use a 45W MagSafe Power Adapter in my MacBook Pro Retina 15 with a MagSafe to MagSafe 2 Adapter.

I am normally using the original one (85W MagSafe 2 Power Adapter) but I just want to know that the computer will charge correctly and that the battery won't be hurt.
It will charge. However, it will do so very slowly.