[zbrox]

I'm experiencing something really similar to what your friend has described. The moment the outside temperature is below 20ºC and my battery is around 30-40% chances are it will die immediately. This started months ago with the update to iOS 10. I tried some of the final public betas of iOS 10.

After several trips to a service point, eventually Apple told me that this is not a hardware issue but a software one and to expect an iOS update that will resolve the issue. No estimates as to when that would be. I asked if it's ok to try the public betas to see if the fix was in and an Apple support rep said it's fine. Unfortunately the latest public beta doesn't fix this. As of now I just assume that my battery indication is off by 40% and I treat my phone as if the battery is empty when I'm out and I see it drop below 50%.