Men jag d ? <| sep |> Right . And you ' re briefly heating the back of the phone , not the face of the battery . Plus , the 3 M strips actually insulate the battery from the body of the phone . In fact , it ' s actually a design feature in using the 3 M tape instead of glueit helps in very low temperatures as the aluminum won ' t conduct the cold to the battery as quickly since it ' s not touching the body and is insulated by a mm of foam tape . Obviously it won ' t help if you leave it in the cold , but it ' s meant to help prevent power starvation when moving from a warm environment like your pocket out into freezing ambient air which can reduce the output of the battery . And since the components inside generate heat , this will warm it a bit , helping offset the encroaching cold , so long as the phone was warm to begin with .