It should be noted that there are vehicles in which specific systems that must have continuously connected battery power, alarming systems, power controls of doors, etc., and also power supply for memorizing the control units, for example, the radio and the indicator of the Powertrain Control Module. To avoid the situation when one gets locked out of the car after reconnecting the battery, it is advised to take the key out of the ignition first. Incorporation of a memory saver device is useful in preserving important features as and when the car is disconnected; the device plugs into the cigarette lighter jack and an extra battery to ensure that the fundamental features are supplied with power. It is recommended that one should shut the engine, switch off all the accessories and properly unfasten the negative cable from the terminal and then the battery disconnected. In case the positive terminal is undesired, it can also be detached following the removal of the negative terminal. For reconnection start with the positive terminal then the negative terminal, and restore the settings that were lost like the time and audio settings. If applicable return the moon roof to default setting by turning on the ignition while holding the close switch until its operational cycle is complete. If back door is open at the time of disconnection, reconnect battery, shut the back door and observe to confirm it is working properly.