Lexus RX400h hybrid battery compartment flooding issue despite multiple seal attempts on Lexus RX400h

Some Lexus RX400h owners report experiencing recurring flooding issues in the hybrid battery compartment, which can lead to costly repairs due to water damage. These problems are often linked to ineffective seals that fail to prevent water from entering over time. Additionally, water retention at the base of the vehicle, particularly after heavy rainstorms, has been identified as a potential cause of computer and hybrid battery failures. Owners have also noted that blocked drain holes at the front of the sunroof can contribute to water flowing into the battery compartment. In some instances, leaks from the liftgate seal have been recognized as a source of water ingress, causing damage to the hybrid computer and traction control systems. Despite attempts to seal off the area, the persistent flooding issue underscores the importance of regular maintenance checks and proactive measures to mitigate potential damage to the hybrid system.