It sounds like the special shops which REQUIRE you to tell then that it is a laptop battery (there is another scenario where you are REQUIRED to tell them that your mother asked you to mail it and you don't know what is in it; you will be instructed as to which scenario you are assigned to complete). This is a test to see if the contract locations are asking the HazMat questions. If they are doing their jobs correctly, they will refuse to accept the shipment, and you say thanks anyway, you go outside, take a photo of the outside of the store, and you are done.
I have done 11 of these shops. Of the 11, 9 of the locations did not ask the HazMat questions and simply accepted the package. Some asked me absolutely nothing. 4 of the 11 were "laptop batteries" and 3 were shipped. Of course, they weren't really laptop batteries, but if asked that is what I was instructed to say.
Slightly more tricky is that you have to report which shipping services was offered first, but you have to manage to ship it using Priority Mail.
On a related note, I was in a Verizon corporate store the other day, and there was a customer there who had tried to ship a phone back to Verizon's warranty service (Asurion) in a pre-paid mailer by UPS, and UPS refused to take it because the phone had a lithium battery in it.
Shopping Southeast Pennsylvania, Delaware above the canal, and South Jersey since 2008