Battles are a "saving grace bonus points" thing moreso than a requirement. If you can write a damn good story without 'em, please, don't write a battle. Most graders will love you more for it. If a lot of your description/plot aspects are borderline, though, or your grammar is completely illegible, graders fall back on the irrelevant categories (length/battle) to make the final decision. These categories are evaluated more for signs of laziness than signs of brilliant quality, in most situations--but if you need the boost, then take the boost.