So, this seems to be a hard question to get an answer to.

Do mobile phones keep working when the power goes out?

Answer #1: They don't legally have to have power backup.

In North America, there is no regulatory requirement for cell phone companies to have systems to keep them online when the electricity goes out, which is different for landline telephones, where some exchanges have been up continuously since the 1920s. 

A guide on how to legitimately open a US Bank account as a Foreigner (Canadians can use this method, or this method without having to leave Canada).