Battery life

I seem to be experiencing battery life issues. I'll charge it up to 100% at night, play golf, end the round and sync with my phone. When I get home, it's at about 75%, which is fine. 

However, after just a few hours, I'll see that it'd down to 50% and then by the end of the day, down to 25%. 

I'm guessing it might be a bluetooth issue? I've tried unpairing/re-pairing but no success.