Does the MPM have an internal power source to maintain the clock during an extended loss of power?
Clock maintenance during a loss of power
The MPM has a Lithium battery that will keep the system clock online/accurate during a power loss. The battery life is very high, however leaving the MPM unplugged for many months will eventually wear out the battery.
Units manufactured after week 13 2016 have a super capacitor rather than a battery. The capacitor has a charge time of approximately 5 minutes after which it will provide backup for the RTC for approx. 48 hours