Before I include these in my package, I wanted to make sure they are laptop batteries.

check the one to make sure it says lithium ion and they would qualify.... But dont send them... Lithium ion batteries are a hazardous material item to ship and have to be treated specially. The fines could be expensive if caught shipping them improperly.

in addition, they are kinda heavy and probably not worth the cost to ship anyway (even at regular mail prices).

One on the right is a laptop liOn battery
One on the left is NiMh and is not considered a standard laptip battery.
Try batterybuyers or a local yard.

Thank you everyone for your help. Very informative. Thank you.

Btw lithium ion batteries are required to be shipped ground in the us. Parcel post, parcel select for the post office.
Shipable hazardous materials for fedex.
Form h for ups. (Used to be haven't used them in a long time).
And rail select for tnt.

Shipping one in a box loose is not likely to cause you an issue but it's a major fine if you get caught. I almost always use fedex so I don't run into that problem.