Abstract In this paper, we propose a new method to corona charge the electret after device packaging, based on the common electret based electrostatic vibration energy harvester (e-VEH) with the out-of-the-plane gap closing scheme. Combined with a new portable corona charging system, the electret in the device has been charged successfully. Here, new portable corona charging system is designed to be powered by another e-VEH directly. In our demo, one e-VEH powers the portable corona charging system first, and then the system releases the energy to corona charge the electret in the other device through some build-in corona tips. After charging, the electret possesses a uniform surface potential, and the device shows a better power output then before charging. In the future, if the surface potential of the electret decays after the e-VEH has been working for a long time, we can also use this new method to recharge the electret directly.