Leaving the lights on overnight in a hybrid vehicle can lead to multiple negative impacts, primarily concerning damage to the 12V auxiliary battery. Although hybrid models are equipped with high-voltage traction batteries, electronic devices such as lights are still powered by traditional lead-acid batteries. Overnight discharge will cause the battery voltage to drop below the critical threshold, potentially triggering the vehicle's protection mode and preventing the hybrid system from starting the next day. Even with a fully charged high-voltage battery, a depleted 12V battery will disrupt power supply to the vehicle's electronic control system, resulting in failure to switch to READY mode. Prolonged occurrences will accelerate sulfation of the auxiliary battery plates, with replacement costs ranging approximately from 300 to 800 Malaysian Ringgit. Notably, some hybrid models feature an automatic power-off function, but this safeguard typically activates only 30 minutes before complete battery depletion, failing to fully prevent damage. If battery depletion occurs, attempting a jump-start or connecting an emergency power supply via the vehicle's OBD port can activate the high-voltage battery's charging function for the 12V battery.
