Didn't know where to put this thread, but since it is battery related. I thought I would post it here. Since I've overheated 2 of my li-po packs by drawing too much current and producing too much heat. I kept thinking of some easy way to check the temperatures when it struck me that some of the Duracell batteries comes with a neat little battery tester. This is basically a temperature sensitive display similar to those found in fish aquariums. I took one and added heat to it and found it to light up at 110 degrees F' This seems a safe range since I've read 140' causes damage. I do not intend to get that close to those temperatures. It's easy to cut up a piece of the material and tape it to the battery for a visual instead of touching it or measuring it each time to verify if it's getting hot.