Lightfire, you've made several posts now that are confusing AMPS, an instantaneous measure of current flow, and amp-hours, a cumulative measure of current flow over time and the mathematical product of amps times hours. So your request for "12 ampere per hour" is nonsensical. If it can generate 12A, it can do it forever until it breaks. Don't worry, many people make this mistake. Many are confused about kilowatts and kilowatt-hrs.Anyway, it would be possible to make a 12 volts generator? Let's say 12 ampere per hour.
With every small DC motor I have tried, a finger spin is enough to pulse an LED.If you are using dc motor ,you may need gears or other method to speed up the motion.