1. It's not "poor maintenance" that is responsible for a flat battery on a C152 at YMMB, it's stupid bloody pilots and instructors who fail to turn off the master switch.
2. Other than that, the comments about chocks are correct. Having said that, as a student in a C150 with a flat battery, I knew enough to keep my feet on the brakes and how to operate the ignition switch to keep the Two people (one supervising and one starting) safe.