I'm trying to create this prototype where I will require constant charging power for a sensor i will install on a trailer (container truck trailer). However, due to some problem, I wasn't able to tap power from the truck's own battery power.
Hence, I'm actually thinking of an solution where I will install a separate independent charging source to charge my sensor. For example, it could be a solar panel. However, solar panel is not optimal because some times the trailer might be indoors. I am thus wondering if there are any other ways to generate energy, such as a dynamo or alternator etc. I'm open to any ideas!