Armour gizmos charged with perks can be used to enhance the shield's abilities. As an off-hand slot item, the Augmented Bandos warshield can hold 1 gizmo, allowing up to 2 perks.
Using this shield in combat can gain experience to increase its level. Levelling the shield will have no effect on its ability in combat, but it will improve the experience and materials gained for disassembling it.
The Augmented Bandos warshield uses charges stored in the universal charge pack. When the charge pack runs out of charges, the item loses stats and gizmo effects, and can also no longer gain any equipment experience. Function will resume when the pack is recharged with divine charges.
Your current drain rate for a tier 70 off-handed weapon is given by the following table. It depends on your current reduction researched, the item level, and Efficient/Enhanced Efficient perk presence.