weirdest thing happened today at work...I need to replace a sensor in the wifes 07, was looking on ebay, almost bought a set of 4, but thought I'd wait to decide on if wheels were staying or going...whatever, Ive never seen a tpms sensor except pics on ebay yesterday...today one of the machinists walks up to me and says" any idea what the heck this is?"- its a blue ford tpms sensor- we make wheels, one musta came back on a skid or something and fell on the floor, he picked it up...what are the odds...anyway looking at it, noticed the little recycle icon on it for Lithium Ion battery inside...read a bit I guess they have 5~10 year non replaceable batteries inside, and below the part number is a date code(I think) this one says:

pbt-30 gf
fcc id:k08ftd06a
ic: 3521a-ftd06a
e778f (assume this is a date code)

Anyway, got me wondering if the ones on ebay may not be the best deal as perhaps theyve been on the shelf a couple years or something- anyone got any idea on if these things are date coded, and how to decipher it?
I thought at first, cool, I'll pop it in tonight and fix her light, but dont want to put a old sensor that might not have a year of battery life left...still think its really funny that a day after looking one up on ebay, a guy happens to find one on the floor and asked me about it...