The simple answer is that your new light is a LOT brighter and probably makes you more visible from a longer distance than the ones that go for weeks. Up close, it might not seem much brighter, but I bet it is at more distance. Hopefully it has a lower steady mode, or a slow pulse mode that burns at a lower rate you can use for a longer ride. I would use this on high for a commute, or a ride that starts in daylight and only need the tail light for an hour or so at the end. The better lights let you chose a mode that balances brightness an run time to fit your ride. If you want a super bright light that runs all night, you're going to spend some money and it will probably have an external battery pack.