A charge leveler coupled between an external power supply and a data storage device includes a current limiter to receive an input current from the external power supply and to provide a limited input current at no more than a pre-determined level. A charge reservoir couplable in parallel with an output of the current limiter supplements the limited input current when the pre-determined level is exceeded. The charge reservoir is replenished with surplus limited current when the data storage device draws less than the pre-determined level. A boost assist regulator monitors a requested current from the data storage device, and initiates operation of the charge reservoir to supplement the limited input current when the requested current exceeds the limited input current.