iPhone crashes/ battery percentage wrong
Over the last four days my iPhone 6 will freeze and then crash. It says that the battery is low when I try to power on but the battery appeared to be okay when it crashed. I restored the iPhone to the last backup after the first two crashes but it crashed again. I've seen that other people have stated that their battery percentage gets frozen. I noticed that it happened to my iPhone 6 today (it literally said 100% all day despite not being charged since the early morning.) This all seemed to start happening after the 9.3.1 update.
Has anyone else experienced this? Is there a known solution?
iPhone 6, iOS 9.3.1