With continuous, you are going to have around 12 hours of battery life. With voice activation you will have at most twelve hours of recording, but possibly less depending on how many times (and how long each time) the pen is paused. The pen will still be using battery power while paused, so if it pauses a lot you will most likely get less than 12 hours of recording on a single charge (but that recording will be void of dead spots, which is a good thing).