Apple iPhone 6s review: The more it changes…: Display, battery life, connectivity
Battery Life and Charge Time - The Apple iPhone 6s and iPhone 6s Plus Review
Exchangeable Battery for iPhone 6S+/6+, iPhone 6S/6?
iPhone 6s - Battery usage only 3-4hours - Apple Community
WAVYPO Battery for iPhone 6S, Upgraded 3200mAh High Capacity New 0 Cycle Battery Replacement for iPhone 6S Battery A1633 A1688 A1700 with Full Replacement Tool Kit