I use this gadget whenever I have a questionable cable. X-DRAGON USB 2.0 Digital Multimeter Power Meter Tester Current and Voltage Monitor, Test Speed of Chargers, Cables, Capacity of Power Banks (7 Modes Monitor, dual USB ports, Accuracy) https://www.amazon.com/dp/B019RHJRM8/ref=cm_sw_r_cp_apa_i_qOAwCbHNHJZV2
Try going into settings>apps and on the 3 dot menu (upper right hand corner) go into app permissions>location and turn off permissions for those apps you don't really feel necessary they should have access. Also greenify is a great application to save battery life: https://play.google.com/store/apps/details?id=com.oasisfeng.greenify