These gauntlets have 30 charges and regain 1d20 + 10 charges at the end of a long rest. When you would take Acid, Cold, Fire, Lightning or Thunder damage, you may use your reaction to spend a number of charges equal to the amount of damage you would take. You must choose to reduce the damage before the damage is rolled. When you do, reduce the damage you would take from that damage to 0.

If you would expend more charges then you have left, the gauntlets fail and release all stored energy in a blast of explosive force. You, and each creature within 10 feet of you must make a DC 15 Dexterity saving throw. On a failed save they take 3d10 force damage and are knocked prone, or half as much on a successful one and are not knocked prone. 

When the gauntlets explode, they become unusable for 1d10 days as they recharge. If you attempt to use the gauntlets before then, they automatically fail and the recharge time doubles. 

Notes: Combat, Warding, Wristwear, Artificer