On Hybrid vehicles, the 12V battery lead remains live, even when the 12V battery is disconnected. Suitable precautions need to be taken by qualified personnel. Failure to do so may result in serious injury or death. Consult a repairer/authorized repairer.
Disconnecting the battery can affect a number of vehicle systems, especially if there is insufficient battery power before disconnection. For example, the alarm may trigger, depending on its state when the battery is disconnected. If the alarm does sound, use the smart key, in the normal way, to disarm the security system. The windows may need recalibrating to operate correctly.
After reconnecting the battery, a number of systems may need to be reset.