Battlemage Armor is the chestpiece of the Battlemage Armor set.
Arcane Compendium Entry
Granted only to mages who have proven themselves true masters, Battlemage Armor offers a good amount of protection. It has higher durability than Mage Armor, but has a slower repair rate and less enchantability, as well as giving lesser versions of the magical bonuses that mage armor does. Battlemage Armor can also be given XP which will unlock protective spells that will come to the aid of its wearer, draining some of the magic within the armor. The magic will then infuse back over time from your own mana pool.