In this letter, we consider a large scale network where multiple devices are wirelessly charged by power beacons (PBs) using millimeter wave. We propose a directional power transfer scheme to better utilize beamforming (BF), i.e., each PB steers its beam toward the BF direction in which it receives the maximum power during the training phase. The devices harvest the aggregated power from the PBs. Using stochastic geometry, we derive the approximated expression for the power coverage probability. Our results show that the proposed scheme is feasible for the dense deployment of PBs. Additionally, it generally outperforms the random BF.