How to: Check iPhone battery health, DIY replace, and speed up performance

How to: Check iPhone battery health, DIY replace, and speed up performance  9to5Mac What I hate most about Apple slowing down iPhones with bad batteries  BGR Apple Says It Slows Older iPhones To Save Their Battery Life  NPR iPhone Performance and Battery Age - Geekbench  Geekbench Apple confirms iPhones with older batteries will take hits in performance  The VergeFull coverage