my brother works at a (caddilac dealership) who also sold BMW cars.. this solar charger came with new BMW cars its a 12 volt trickle charge maintainer, i wanted to see if it could run my fish finder for thru the ice fishing and it worked great for that it kept my small 12 motercycle battery in full charge all the time and i have it used it alot,, i will just mount it now to the hood of my garden tractor so when out in full sun ,it will charge the battery for starting as without the generator it would lose the charge needed to run any lights or the starter, thus eventually id lose the spark to engine with no generator so ill try it on my tractor it should work well,, to keep me going ,, i also found in my area an old time parts yard for International farm tractors like the m and h tractors used on farms. they some times had about the same charging systems with a generator on them like i need for my garden tractor, im seeing first hand that one in working order is like hair on a frog or teeth on a chicken but who knows ,ill come up with something and soon ,for very little money but i have lots of time in the search !!! hopefully it will pay off in the end and i dont get the shaft!!