(I'm going to get back on the idea bandwagon. Who let me fall off? Oh, I did. Anyhoo, I want to do a deep green idea per day instead of just random ideas. A more targeted and eco-friendlier firehose...)
How about a new kind of battery monitor that uses a baseline heat signature to tell you whether or not the battery was still good? Thermometers are cheaper than ever. I am so tired of my batteries showing full and then leaving me huffing and puffing up 15th from University District on my Ezee Quando electric bike. Give me a better monitor, stat!