what are you using for a smart key fob tester? I have seen a few that show different frequencies, on them, but I'm not sure how you are to tell which fob would have which frequency.
I tell most our customers that if they have a message on their DIC, then it needs a new battery, but some still want them tested. With the tester that we have it just shows if it is putting off a signal, but not whether it's putting off enough signal to allow the vehicle to start.