The question is … when you get a refurb keyboard/mouse like this with a LiPoly battery, how many cycles are on the battery? did the seller replace the batteries? 
I often buy things “Used Like New” from Amazon, but I see several “renewed” MX Keyboards on Amazon being sold by and shipped from “Ziko Electronics.” Don’t know them, don’t know whether to trust them. If you assume you get a unit with a year old battery, you may have to do the replacement … which then diminishes your savings in buying a “refurbished” Logitech Keyboard. (See the comments on teh iFixit article, owners complain of the keyboard’s battery health declining due to the backlighting.)
That said, these are really great keyboards. Maybe not the tactile feeling (over mechanical, which Logitech sells), but for pairing with more than one computer/device (phones and tablets can use a keyboard, too) these are unbeatable. The Options+ software is great, too.
Anyone know if these with work with Xbox X? I hate typing with the controller and just want a keyboard I can type in passwords and stuff.
According to the Google:
Stupid Microsoft, very stupid.