I notice that the PV450 includes a battery backup for the real time clock. Is a warning message generated when this battery nears the point of failure? How long is this battery expected to last? Is it replaceable?

Thanks.

There is a rechargeable 3 Volt Lithium Ion battery built onto the PCB and it is attached to a Ricoh RV5C34B Real Time Clock. The battery will drive the RTC when there is no power and there is a diode circuit which prevents the battery from driving any other devices on the Display. The backup battery is basically isolated. The Ricoh RV5C34B Real Time Clock use 0.55 microAmperes which should have a shelf life of well over 500 days with this battery. The Ricoh RV5C34B Real Time Clock has a circuit to determine the integrity of the RTC data based on whether the oscillator fails, however if the RTC data fails, the RTC registers still have the best available data, so no error is logged.
To answer your questions; we can not measure the backup battery voltage so we can not detect its point of failure. The RTC backup battery should last over 500 days sitting on the shelf. The battery is rechargeable when the displayed is powered (even for a short time). The PV450 is sealed so it is not replaceable. Without an external clock reference (say from GPS), we are not able to determine an RTC failure so we report what we find in the registers. We do not have a DTC which identifies a Real Time Clock failure.