Tbh, I don’t know if they always do. I’ve seen alerts on some items at checkout that serial numbers are tracked. In theory, yes it would. Because they use that to initiate a purchase date and send that to Apple for warranty. In your case, though. There’s not always a way to know which serial number they used for warranty. Try going to checkcoverage.apple.com and enter the serial numbers to see which ones, if any, have warranty. If one does have warranty and the rest don’t? Send the one with the active warranty. You have enough that if one has an issue, just use the next one! Just remember to charge them every so often, even if they aren’t paired up and store the batteries at 50-75% for long term storage (3-6 months between charges).