To use the rechargeable bulb electric power moves the on/off button of the rechargeable bulb towards the "ac" function and plug into the socket. To turn "on "the rechargeable bulb push/press the switch on the wall towards "on" position and to turn "off" position. To use the rechargeable bulb using the in-built rechargeable bulb towards "dc" function. When rechargeable bulb is turned "on" on "dc function" and plugged in to the socket and if the electric power is "on" it will charge the in built battery but rechargeable bulb will turn "off" then the rechargeable bulb will turn "on" by using the power from the in built battery this is called automatic emergency lamination function (AEIF). To charge the rechargeable bulb move the "on/off" button of bulb towards "off" position and plug in to the socket and turn "on" the main power. Note it will only charge in "off" position if the main power is "on". There is a small red color led indicator near the on/off button indicating the status of the charge. Do not charge the unit for more then 12 hours at one time. Charge the rechargeable bulb once in every 2 months if the rechargeable bulb is not used continuously for 2 months. Avoid looking directly in to the led's as it has a strong beam.