An auxiliary refrigerator; used to for emergencies, holding overstock, items not allowed in the main fridge, and, regardless of other contents, beer.
The battle fridge is smaller and less well-lit than the main fridge, and is located in a different part of the house, such as the den, the garage, or the Engineering Section.
Dan: "You got anything to drink?"
Jon: "Check the beer crisper"
Dan: "Dude, it's full of vegetables!"
Jon: "To the battle fridge!"
Having the toaster, waffle iron, and deep-fryer all running from the same outlet blew the fuse for the whole kitchen, but by the time we figured that out, all the meat and dairy in gone rancid. Luckily, we kept extra cold cuts, cheese, and beer in the battle fridge.
"The wife doesn't let me keep my weed-infused bacon grease in the kitchen, but there's a mason jar full of it in the battle fridge"