I think the iphone 6s bettery is bigger by around 300 amh but most of the extra battery is wasted by the bigger screen. I tried the airplane mode thing twice before(though since my iPhones battery messes up and sometimes has more percent when it turns on than when I turn it off, neither times were fair. In fact the first time the battery was dying instead of charging. The bigger just curious how long does your 5s last with mild usage and how long does it take to charge?