10k miles bulging battery acid leaking

Well that is the most likely explanation so.....

If you leave a battery dead for a long period of time, especially in the cold, the battery can easily go bad. When I worked for a large BMW dealership where some cars would sit for months at a time with dead batteries we were replacing like 2-4 batteries every month on brand new cars before they were even delivered, given we had over 600 cars in stock at any given time so I wouldn't call it a BIG problem but it was common enough.

 

My battery has an unusual amount of corrosion on it, the bracket already has some rust on it. Truck has been in for every scheduled 5k maintenance. Literally the battery looks worse than some I've had for 3 or 4 years in decade-old vehicles. Definitely going to have dealer address it when it goes in for CPS Recall.