MNGP coin battery life or current draw? What is being kept alive?

[Sweet Taterman]

This is my first question posted to the forum. I strive to be a reasonable forum user and have read the FAQs as will as have spent a few hours reading threads with subject lines of interest to me. I will try to confine each new thread to a single topic or closely related topics to ensure that the subject line will be useful to others at a later date.

I am checking out a newly purchased Classic 150 with the most current firmware. Once I am satisfied that it functions as designed and I understand it's operation it may remain unpowered for long periods of time. The coin cell battery in the MNGP is a CR1216 cell which typically has a capacity of 35mAhr. What is the current draw from the cell while powered down or alternately and equally useful how long will it last? If the answer is more than 4 uA or alternately less than 2 years, I am interested in the questions below.

What is being sustained other than running the clock? If the battery is rundown or removed are the user adjusted parameters lost?
As an aside, page 9, Rev C of the quickstart guide says "...for the Clock and non-volatile memory to store its data when the Classic is powered down". My understanding is that is non-volatile=power not required and volatile=power required.

Is there a "hold up" capacitor incorporated in design so that the coin cell can be changed out without losing any data/function?

[Halfcrazy]

My understanding is the coin cell will last for 3-4 months or more with no wires connected to the Classic. It's ONLY job is to keep the time and date. All user settings are saved in non volatile memory for ever until over written. You can change the coin cell while the classic is powered and date and time will not be lost how ever I can not say if you can change it with the classic de powered and expect the time to stay. I am assuming no but boB should have a better comment on that.

Ryan

[boB]

I can't remember how much current is drawn from that little coin cell but I wish it was less than it is.
When the Classic is powered up, it shouldn't draw anything from it.

The time and date is the only thing that is held up by that battery in the MNGP.  The Classic
control board itself also has a time/date calendar but no battery backup.  The MNGP tells
the Classic the time and date every minute or two when it is connected IF the Time Synch
option in the TWEAKS menu is ON.  In older firmware, the MNGP Time Synch could not
be disabled.

boB

[niel]

i turn my classic off and back on the next day and my battery lasted about a week or 2. i don't need to have it in there, but it is annoying to see a constant reminder going on the display off and on to set it every time i repower it up.

[boB]

i turn my classic off and back on the next day and my battery lasted about a week or 2. i don't need to have it in there, but it is annoying to see a constant reminder going on the display off and on to set it every time i repower it up.

The latest firmware only nags you for the first half hour or so that the time is not set.

So, that message should go away after a while.  (hopefully)

boB

[niel]

boB,
taking note that i will need to view that more closely before turning it all off next time, but it doesn't matter that much to me even if it would still be there or not as i usually don't watch it that long.

my real point was the length of time the battery lasted and only those that totally shut off their classics are affected. graphs may still show as with other info, but a time and date will not be accurate to some of this as every power up reboots the time and date. i did not view the graphs to see the real effect just as long as my current info stands correct i'm happy.