My son has one of these batteries for his phone ( don't know the model) but being a member in the paranoid what-if camp, I carry with me a second (cheaper model) cell phone whenever there is any hint of anything that requires extra precaution.

This second phone is leftover from my kids collection. I decided to give it a new home in my EDC bag instead of the junk drawer.

So BPJ, if your kids ( senior and junior ) have thrown away some older phones, it's time to grab one of them.

Oh, and my older spare phone has a built in torch, so it doubles as yet another flashlight.