Because a friend asked: Despite recent events, we rarely lose electricity at our house. But when we do, you can bet at least one of our cell phones or Kindles is in desperate need of recharging. A year ago, I bought a USB power bank that you keep charged up; when the power goes out, you can hook up a USB device for recharging with no need for electricity. It saved our butts earlier this week, so I ordered a second one. Very inexpensive and highly recommended as a precaution.