05-05-2016 21:11
05-05-2016 21:11
05-06-2016 06:49
05-06-2016 06:49
Hi @Anniepie welcome to the Fitbit Community! I'll explain why you don't have to compare wrist trackers clip based trackers. Fitbit wrist-based trackers have been tested extensively against the clip-based devices like the Fitbit One and Fitbit Zip. That said, because wrist-based trackers are specifically designed for your wrist, if you move your body a lot and not your arms (or vice versa), you may get a slight difference in activity than you would see on your clip-based trackers. Additionally, since you're more likely to wear your wrist-based tracker 24/7, you may count a few more steps.
Now regarding the battery, I understand that you prefer to use the Zip instead of the Flex so you don't have to charge the battery every 5 to 7 days.
Let me know if you have more questions! I'll be around!