536HP internal clock. Mobile scanner

I currently have my 536HP setup in my truck for mobile scanning. I have the power to the scanner setup to go with my ignition. For some reason with the cold NJ weather or whatever the cause my 536 is not always storing the time and forcing me to key in the date and time whenever I start my truck.



Is there a way to stop the internal clock on the 536 from constantly requiring a reset? Or is it an internal defect with my scanner.