Hey guys. I just ordered my Xiaomi Yi and i was wondering if someone can tell me for how long can it record a 108p/60 video before the battery dies and what will be the size of the video file. I am asking this because i intend to use the camera for my mountain bike rides which usually last around 3-4 hours so i want to know how many backup batteries should i carry as well as the size of the micro-sd card i will be using.