BoRccdit A19 Rechargeable Light Bulbs, 12W Emergency Light Bulbs for Power Failure, 1200mAh Battery Light Bulb, E26/E27 5000K Daylight LED Light Bulb for Home Daily and Emergency UseEmergency Lights for Home Power Failure Those emergency light bulbs can self charging when the rechargeable light bulb is on. These battery light bulbs built in 1200mAh battery, which will provide 4 5 hours lighting during power outages. Standard A19 Size & Work as regular bulbs A19 E26 E27 rechargeable bulb is standard LED light bulbsand. It works as regular bulb during daily use but it will charge itself automatically and prepare for power failure