Emerging wireless charging technology has received much attention in the wireless sensor network (WSN) because it achieves the perpetual operation of WSNs and forms the wireless rechargeable sensor network (WRSN). This thesis considers the WRSNs where plenty of static sensors are regularly deployed to monitor the suspicious events. Mobile chargers aim to re-charging energy to sensors and collect their sensing data in an efficient way such that high monitoring quality and small data reporting delay can be achieved. This thesis proposes four charging strategies for mobile chargers and then conducts analyses for the event detection quality of each strategy. Moreover, this thesis proposed an efficient dispatching algorithm for mobile chargers to enhance the event detection ratio with a number of mobile chargers. Based on the performance evaluations, this thesis generalizes better parameter settings, including energy allocation between tasks of sensing and transmitting, and movement speed of mobile chargers, to improve the event detection quality.