Took the jag out for a short outing yesterday as it was a beautiful sunny day and it had been setting idle for about 8-10 weeks. It was connected to the battery tender the entire time. Started right up, no issues, and I drove away. When I turned on the radio, it required the code to operate. Anyone know why this would happen as it was on the tender the entire time?

 

I have a tender that if put in the maintenance setting will draw down the batteries to nothing and then charge them up, over and over and over.
I guess this it to prevent or remove oxidization from forming on the lead plates.
Once the voltage is low enough the memory would be gone from the radio


Might be what happened