Install to hibernate background apps. Servicely or Kernel Adiutor can manage wakelocks.
The SM-T280 has a different chipset (Spreadtrum vs. Qualcomm/Exynos on T285). Using the wrong CF-Auto-Root will brick your device. t285 root 5.1.1 cf auto root
Specific to the SM-T285 on Android 5.1.1. USB Cable: Use the original or a high-quality data cable. Step-by-Step Rooting Guide Follow these steps carefully to root your SM-T285: 1. Prepare the Tablet Install to hibernate background apps