Thank you very much for your very logical response.
The temperature at the time was approx. 15 degrees when I put on seat heater and rear defroster.
After having car on battery tender all of last night the seat heaters and indicator lights worked fine today.
I also experienced the clock problem when I owned a 1 series with comfort access. The dealer diagnosis was weak battery because the car was not driven very much. However, they did cover a new battery and suggested that I use the battery tender which I did on my 1 series and never had a problem afterwards. That is why I have continued to use the tender on my E92 and never had any problems with starting, clocks shutting off, etc... In this recent instance, the clock, heater etc. did not shut off and the only problem I had was the shutting on and off of the seat heater indicator lights. This seat heater indicator light thing was the first glitch that I have had and it has been quite cold here in New Jersey for the past week or so. My garage is not insulated. Perhaps my battery was a bit run down from the single digit temps we have been having until I placed it on the tender last night. I usually put it on the tender once a week for 12 hours or so and get indication from tender that battery is fully charged. Maybe during these extreme cold spells I need to use the tender more often.
I have not had my battery checked in several months and I believe that it may be OEM original lead acid based and not AGM. Do you think that since battery is 5 years old I should have it checked now to see if it needs to be replaced, or just let the dealer do a full diagnostics which I scheduled for Tuesday but was thinking of cancelling since my seat heater and indicator lights worked fine all day today. What would your opinion be?