I love/hate this device. it was cheap. luckily it recognized my 48v battery on its own and i didn't have to set any parameters because the instructions are absolutely terrible. the menu choices and scrolling aren't easy to navigate or figure out on your own, nor could values be changed easily. having said that, i plugged my battery connections in, as well as my solar panels, and it figured itself out. i am unable to utilize all the features because of impossible menu navigation. it's doing what i need it to do in a small setup, "plug and play", so it gets 3 stars.