This kit is termed as High intensity Energy efficient emergency light. In this kit there are two sections -the supply source and the battery source which is mention as a chargeable battery. When there is power available, the LED matrix will glow with the help of it and sideways the battery will also get charged which is of 12v but when the power will get off the LED matrix will be still turn ON but the power source will be battery which will be charge previously. So the system can be used in both the cases thus termed as emergency light.
In this when there is power available the relay activate the supply across the lamp and sideways the battery will get charged. In the later case the relay deactivates and switches the battery supply across the lamp and the since the diode E1 (IN4007) is reversed biased that means negative terminal of E1 connected to the positive terminal of 12 v chargeable battery and vice –versa so in this case the current doesn’t flow towards the adapter but towards the lamp.