The folks at iFixit have torn down the iPhone 6s, confirming a 1,715mAh battery that's comparatively smaller to the 1,810mAh battery in the iPhone 6. The likely explanation for the decrease in battery capacity is the introduction of the Taptic Engine and a thicker display.

iPhone 6s battery

The display assembly comes in at 60g — 15g more than what was seen in the previous generation — on account of the new capacitive sensors that make up 3D Touch. Here's a look at the hardware powering the iPhone 6s:

  • Apple A9 APL0898 SoC + Samsung 2 GB LPDDR4 RAM (as denoted by the markings K3RG1G10BM-BGCH)
  • Qualcomm MDM9635M LTE Cat. 6 Modem (vs. the MDM9625M found in the iPhone 6)
  • InvenSense MP67B 6-axis Gyroscope and Accelerometer Combo (also found in iPhone 6)
  • Bosch Sensortec 3P7 LA 3-axis Accelerometer (likely BMA280)
  • Toshiba THGBX5G7D2KLFXG 16 GB 19 nm NAND Flash
  • Universal Scientific Industrial 339S00043 Wi-Fi Module
  • NXP 66V10 NFC Controller (vs. 65V10 found in iPhone 6)

Head over to iFixit from the link below for further details, and images from the teardown.

Source: iFixit