Dead batteries just replaced in December. Been charging for a week
I replaced my batteries in December of 2018. Went out a week ago to drive my truck and it was completely dead - not even enough juice to turn on lights/radio/etc. It had only been about 2-3 weeks since I last drove the truck. I put both batteries on tenders and here we are a week later and still totally dead. Any suggestions?
2015 GMC 2500HD Crew cab/short bed Sierra Denali