Arlo, I see you are in pa. also. I am in western pa in Mercer County which is not a good area for solar panels because of the excess of cloudy weather. How long have have you had your system? A grid connected system is a lot more cost effective than a battery system ever could be. Car battery will not last long because the plates are thin so they can give a large amp output to start your car. You need deep cycle battery such as sweeper battery or golf car battery that are designed with thicker plates so they last longer. There is an alternitive enegery company in arizona that has a good forum that is has lots of members that help new people learn about solar power. That is where I learned about how to setup my system. The forum is called Arizona wind sun solar forum I couldn,t figure how to attach the address but if you google the forum name I gave you can learn a lot from there to help you design your system.