I asked this question on druid grove. here's the answer:
It's for tinkered Gnome Warrior / Cleric-only armor (warrior / cleric only because it is "plate"). Every peice (I believe every peice, possibly only certain peices) has 10 charges of an effect. I beleive leggings are an effect like Jboots (different name) arms are a fairly nice haste, dont remember the others. But yeah, you use the batteries to recharge the items. The AC is the same as fine plate I believe and it has it's own texture (the helms are pretty neato)

Cogs
Deluxe Toolbox
Greasy Diagram Book
Mana Battery - Class Five
Mana Battery - Class Four
Mana Battery - Class One
Mana Battery - Class Three
Mana Battery - Class Two
Steel Wire
Velium Lens