Try connecting with Bluetooth,and keep it on.
Set cellular and WIFI to automatic.
Turn forwarding off.
This is assuming your watch is correctly set up to duplicate your 'main' phone number (If you call someone from your watch, when it is away from your phone, they see your main number as caller ID.)
My S3 is set up this way. It's been off the charger since 1200, and it's now 1930 (7.5 hours). I still have 89% battery left and I don't get duplicates if I move away from my phone.
In the near future there will be an update to the S3 to provide something that solves this issue. Not sure if the S2 will also get the update.