One SKS works fine other one sks smart functions stopped working

Just changed the oil and rotated tires on my sons '05 Prius. Throughout the process smart key features worked fine. Last thing I was going to do was check air pressure in tires and top them off. I have a cheap 12v air pump that plugs into the accessory/cig lighter port that works pretty well, but the car has to be running to power the thing. Every other time I've used it on the Prius I've remembered that it won't work and used another car to provide the juice.

This time brain cramp and I plug it into the Prius port and of course it doesn't work. Then I notice I can't start the car with the key in my pocket and the dash is giving me the "where's the key dummie" light. I try a few times, no good but when I put the fob in the dash the car starts. Then I check the fob's door lock/unlock function and it works fine. It seems like I changed my smart key into a not so smart key.

My son comes over to get the car and I tell him that my fob isn't working (I keep a spare for him) and he says "that's too bad, got to go" and hops in with his SKS and the dash lights right up and off he goes no problem.

So I do a bunch of research here and then some googling. One person indicated that 12v devices in the accessory port can cause the SKS to fail. What wasn't clear is whether or not the damage is permanent or transitory? Did it cook the circuits in smart fob or just confuse the software? and if there is a way to fix the individual Smart Key.

Sorry for the book length tale of woe. Any ideas?

 

Thanks, I think a new battery for the fob is worth a shot as it's small $. I did check the button under the wheel but as ILMPT noted that button would block all the keys or none of them. Hoping that this puzzle proves simple!