Felipe borunda

I have a 2020 gmc sierra denali 2500hd duramax I live in colorado and my truck currently has 16k miles and I got my truck in August of 2019 well one day I went to start my truck and I heard a click while starting indications of low battery so I took the battery's to test and tested good just low so I had them charged truck started fine drove it 2 months battery still were acting low here and there so I just figured the cold and low usage is draining my battery's took a trip to California made it just fine 3rd day after being in California wanted to go LA one hour oway from where we were and stopped to fuel up and the truck would not start showed the low battery indications and truck would not start screens would turn off but would restart once intented to restart ignition.. whent to the autopart store bought 2 battery's and the truck started drove it back it back 5 minutes oway and left it parked next morning started drove to Vegas stayed the night truck would not start after shutting the ignition have it at gmc dealership hope gmc dealership can figure it out