Hello, there, i have a Surface Pro 3 I3, bought on July 2016. My battery used to last about 8-9 hours, just surfing the internet without seeing videos and reading the newspapaper in offline mode. Since last September/October (i believe after some update), the battery only lasts 4-5 hours doing exactly the same things. I usually charged the battery when it went below 10 %, not always, but in 80-90 % of the charges. What shall i do ?