Although flipped classrooms have been increasingly adopted in higher education, there is a lack of investigations on the interrelations between students' perceptions of learning environment, learning approach and time, and academic achievement in flipped classrooms. This study examined the extent to which the relations between students' perceptions of learning environment, academic achievement, and learning approach and time measured by self-reported and log data were consistent among 271 Australian undergraduates. The self-reported data identified two clusters of students reporting using either deep or surface learning approach more frequently. Students who reported using deep approach more frequently also obtained higher academic achievement. The log data also identified two clusters of students using either a preparation-oriented or an assessment-oriented learning approach, with the preparation-oriented learners having higher academic achievement than the assessment-oriented learners. Students with more or less favourable perceptions of learning environment demonstrated differences in their learning approach and time though the differences were not consistent across the self-reported and log data. While learning approach and time measured by both types of data significantly and positively predicted course marks; the observed learning approach and time could explain more variance in students' course marks. These results seemed to suggest that log data could be more sensitive and accurate indicators of learning approach and time. To foster high quality learning in flipped classrooms, teachers should raise students' awareness of the importance of pre-lecture online learning activities and design assessment tasks aligning learning activities.