Nope. The 1650mAh battery of the Lumia 820 takes something like 2 hours to charge with the nokia charger. But all that matters is the charger. It takes ages to load on an pc.
If your using the Nokia Charger:
- make sure you plug in correct
- use the standard cable
- make sure the phone is in idle
-(make sure to plug in charger first to the wall after that to the phone)