A real favorite! https://books.google.com/books?id=WHPrAwAAQBAJ&pg=PA54&lpg=PA54&dq=battery+over+temp+warning+light+circuit&source=bl&ots=bVq-NCbTBk&sig=YdoLwXvGTicLb8ldcaW7Gt_VNX0&hl=en&sa=X&ei=AxaXVKLkNIHxggSssYKYBw&ved=0CFcQ6AEwDQ#v=onepage&q=battery%20over%20temp%20warning%20light%20circuit&f=false