is the navi code - 4 digits, Radio code 5 digits, key code 4 digits?
 

? I have random numbers and was wondering if this is correct? I'm replacing the battery because it's like 5.5 years old and people say the OEM ones die without warning. Is there any other code I need to replace the battery? Anything else I need to know?

Thanks

nav is 4 radio is 5 - Other than that when you change the battery that's all you need. imo