It sounds like your bulb is designed to work with a high ac voltage. That means it has some circuitry built in to convert that ac voltage to the lower dc voltage that the LED itself uses. Just connecting it to batteries won't work. Instead, you can easily get an inexpensive 3W LED designed to work directly with dc from a battery. They're available for several different socket types, including E27.
If you want to power the bulb for a few hours, you'll either need larger batteries (e.g. a motorcycle battery to work with a 12V bulb) or a lower-wattage bulb. As it happpens, we've discussed some of the options in a very recent post.:
Mike W.
(published on 02/16/2015)
