Motorola v3 Razr Cell Phone Car Cords

I have two Motorola v3 Razr Car Cords (supposed to conserve and charge the battery), unopened. The price on the tag is $24.99 each. We had the Razr phones and then took them back, which left us with these two accessories still in their box.

What do I do with them? I don't know much about selling on eBay and would have no idea if these would be worth it. Anybody have any ideas?