I just purchased a new battery for my TK 3180 radio. When I push the PTT button the battery indicater drops to nothing and then fashes. If I turn the radio off then on it shows full battery. I know the battery is good because I can leave the radio on all day in scan mode and it works fine. It only happens when I push the PTT. Also how can I tell what firmware I have on my radio? Any help with this would great Thank you!!