Can I change the temp setting on my 720i charger. When charging, if my charger even gets slightly warm it shuts down. Even if the sun light is on it a few minutes it will shut off. It even does it when it's not turned on. If I put it in the shade for a few minutes it will start right up. I have a friend with one and his don't do this. Mine has since I got it and I am tired of it. How can I fix this? This is not the new model.