A charging method and system. The method includes detecting and monitoring by a computer processor, a frequency signal associated with an input voltage signal used for powering power consumption devices at a first specified location. The computer processor generates frequency level data associated with the monitoring. The computer processor receives a request to enable a charging process for charging a rechargeable power source and power source data associated with the rechargeable power source and a user. In response to the request, the computer processor enables a customized charging process associated with charging the rechargeable power source based on the frequency level data and/or the power source data.