Battery Life and Charge Time - The Apple iPhone 6s and iPhone 6s Plus Review
iPhone 6S battery life may vary, depending on which A9 chip is inside [Updated] | Ars Technica
3900 mAh Battery Compatible with iPhone 6s- EMNT High Capacity A1633/A1688/A1700 Battery Replacement 【New Version】 with Repair Tool Kits and Instructions【2 Years Warranty】.
iPhone Battery and Performance - Apple Support
Samsung vs. TSMC: Comparing the battery life of two Apple A9s | Ars Technica