Instruct: Classify a given review into positive or negative sentiment.
Query: Let Me Down When Tornadoes Came

I bought the Black and Decker Electromate 400 Power Station for my wife when our girls developed the bad habit of flipping on interior lights in her van and draining her battery. I would have just bought an extra battery and a trickle charger, but I thought the Electromate Power Station would come in handy in an emergency. It worked great for a few months. Then I left it on charge so it would be ready in case of emergency. When tornadoes swept through Northern Alabama and the power was out, I turned to my Electromate Power Station to keep my cell phone charged. It failed. Somehow the battery was totally drained, despite having been plugged into the wall up until the power outage. I'm disappointed to have wasted my money on a piece of emergency equipment that failed me when I needed it the most.