Electrical system shut down and would not enter sleep mode

I ran into this just a couple days ago. Out of the blue the electric in the Pebble shut down. Support had me plug the 7-pin into my truck to get it to go to sleep since it would not go to sleep on its own. Once that happened it was able to restart. The tech told me it was the 12V battery. I’ve used my Pebble for about 3 weeks now.