Nest Protect Expiration Date

I just bought a set of Nest Protects and after opening the first one I noticed that its manufacture date was almost a year ago and that the expiration date was 10 years from the manufacture date, not from the install date. So effectively the units cost 10% more than their list price.

My reading of the Nest Protect manual is that the units will start nagging you to replace them a couple of weeks before the expiration date and that they will become quite insistent once they “expire.”

A call to Nest wasn’t too productive, but I did learn that:

• I shouldn’t expect the Protects to last 10 years – more like 7 or 8.
• They actually start counting the 10 years from the install date – but supposedly this doesn’t show up in the app. If I want to check the expiration date I can look at the back of the unit… Hopefully what they mean is that I can calculate it myself from the install date that I can write in the space that they provide.
• That if I want to get fresh units I can have the store open them up for me to check the expiration dates (they are not printed on the outside of the packaging).

Needless to say I’m underwhelmed by the quality of the support.

Does anybody know:

• If the date does show up in the app?
• If it does, is it recalculated based on the installation date?
• How the Protect behaves when it reaches its expiration date?
• The typical age of units in stores (i.e., is the retail pipeline really almost a year long)?
• Sources that are likely to have fresh stock?

Thanks. I think I still like the units, but would sure appreciate better customer support.