My battery is 85% healthy, 2013 11 inch MBA, only 250 cycles. In El Capitan, used to have up to 8 hours of battery life, battery health was also 93% or so. After Sierra install, the battery health in a month worsened to 85%, battery work time fell to 4-5 hours. Tried a new fresh Sierra install, PRAM and SMC reset - nothing helps to recover the battery health. So I wonder why Sierra shortens the battery time and aggravates its health, and is there any remedy to it, except installing El Capitan?