This paper considers the effect of variation of load resistance as a function of state of charge of battery in the concept of magnetic wireless power transfer. We have calculated the load resistance as a function of time, and shown that load resistance will increase as the receiver acquires energy over time. We have proposed a combination of topologies at the receiver that can harvest more energy compared to current available circuit models. Unlike previous studies that considered resonance frequency of transmitter and receiver is always a constant value, and once you have fixed it, it will remain unchanged; we will show that for the case of parallel resonance topology, resonance frequency will change as the load resistance varies. To avoid performance degradation due to the unmatched resonance frequencies between transmitter and receiver, we will consider a periodic feedback from receiver. Considering the cost of feedback, there is a trade-off between the number of feedback that receiver sends, and the received energy at the destination. For a point to point system model, the optimal feedback duration that maximizes received energy has been calculated. The numerical results show that the proposed protocol receives higher energy compared to existing point to point magnetic wireless power transfer system models.