Wireless relay network is a solution to extend the reach of a wireless connection by installing a relay node between the source node and the sink node. Due to the broadcast nature of wireless transmission, the sink node has a chance to receive part of the data sent by the source node. In this paper, we apply a network coding scheme called BATS codes on a wireless relay network where the relay node has a stable power supply, so that we can aim for the best decoding time instead of minimizing the number of transmissions for saving energy. We optimize the time efficiency that maximize the average decoding rate per unit time by some heuristics, and bring out a message that it is not optimal to set an average number of recoded packets per batch at the relay node equals the number of packets per batch sent by the source node.