It's the dB4LW. I can take a 100km trip to the mall - although it depends on how long I am inside, because in certain areas it will run constantly. Also as I ride past certain electronic doors. I just check to make sure the thing isn't past my normal distance on my commute and don't use it until I have caught back how much was artificially added. Other rides I don't normally go into stores so it isn't a problem.
The other thing is I haven't bothered with it for a month - it's on the other bike which needs wheel attention.