I have an iphone11. I have never used my phone to play back music before when going on walks, but the last couple of days I have. I go for 1 hour and 15 min walk, playing music from iTunes. When I get home the phone is warm and the battery has dropped in half. Since I got this phone late last summer it has had great battery life. Just wonder if this is normal. I probably will get back to using my shuffle for walks.