Stefan Mileschin

"Just a year after the release of the original Mi Band, Xiaomi announced its upgraded version, Mi Band 1S, adding on a heartbeat sensor. One the biggest sell points of the Mi Band and the Mi Band 1S was the quote 30 day battery life, even though I got more than 45 days out of mine, which meant that you didn't have to charge it on a daily or weekly basis.
Fast forward another year, and with as much anticipation as its previous 2 iterations, Xiaomi announced the Mi Band 2, this time sporting an OLED screen to display the time and an actual physical button. Still priced at a bargain RMB149!"

http://www.funkykit.com/news/gadgets...band-2-review/