This thread is based on the work of nikdfish and his post "Bought the wife a dump trailer". He did all of the real design work. I have modified it to fit my needs. I store my trailer in the yard, facing any direction I drop it, when not in use. Best results for solar cells is south facing. Hence a moveable mounted device. I have noticed that I am always removing dirt, mulch, sticks and twigs from the top of the front control/ battery box. I need a removable system. I also hate to drill holes in a flat waterproof lid. I added some angle brackets to shed rain and face the sun. For mounting I added 2 harbor freight magnets ($ 4.99). Lastly I wanted to be able to remove the entire system when using the trailer, hence the battery spring clamps. . I will add a inline fuse this week. Need the dump trailer, hook up , open lid, unhook from the battery, remove the entire solar system. Thank you nikdfish for your design idea, parts sources and construction details.