A few months ago I boosted a friends 300... that in itself should have you giggling :P
The OEM battery has something like 350 Amps of max output, and I have no idea what "group size" it is, I assumed it was the same as the versa with a 51R but it's not (dimensions are 7" Deep, 8" Wide, 7" Tall + posts, Terminals Reversed (negative on the left))
Long story short, I had to replace the battery, thing showed 12.3V while off but dropped to 5.1V when trying to crank (alternator works fine and outputs ~14V). If anyone else needs a new one and wants "roughly" the same size but a bit more headroom, grab a "Group 47" - it's 8" deep, 9.5" wide, and 7.5" tall but has recessed posts so overall it's within a quarter inch of the OEM's height... and they have a ~700 Amp output. The tray our battery sits on is huge, I still have over an inch on either side.