The Covenant

Charges can be spent for 2 purposes:

a) Recovering a spell slot of 7th level or lower by paying a number of charges equal to the level of spell slot you want to recover +1.

b) Casting a spell at one level higher level than the spell slot you paid (maximum 7th level) by spending a number of charges equal to the final spell slot level +1.

The power of your covenant can only be used 3 times a day provided you have charges for it.