The Rema (673) rules that it is preferable to light the Menorah with olive oil, since that’s what was used in the Bet HaMikdash. The Rema continues and says that if one does not have olive oil, the custom among Ashkenazim is to use wax candles, because they have a nice flame. However, the Mishna Berura (Rav Yisrael Kagan of Radin, 1839-1933) rules that any type of oil is preferable to candles, since in the Bet HaMikdash the Misva was done with oil.
Hacham Ovadia rules that, preferably, one should light the oil with a wick, although, the Sedeh Hemed maintained that a wick is not necessary and one may light the fuel directly. The question arises whether one may light with a Menorah using an electric light bulb, in which the electricity is the fuel (oil) and the filament is the wick. The Poskim are against it for different reasons. The Kaf HaHaim (Rav Ya’akob Haim Sofer, Baghdad-Israel, 1870-1939) held that it is invalid because the "flame" is contained within the bulb and fills the entire volume, it is tantamount to a "Medurah" (torch), which is invalid. Some say a Menorah must be lit with direct human action, like in the Bet HaMikdash, whereas here it is lit via a switch that allows current to flow. Hacham Bension invalidated it because there is never the requisite measure of half an hour of fuel (electricity) in one place at one time, since the current is constantly flowing into the bulb from the outside.. According to this reason, Hacham Bension (Ohr Lesion Vol. 4) would permit using a battery powered flashlight as a Chanukah light with a Beracha, since the proper measure of electric fuel is already collected inside. Theoretically, a person could line up eight flashlights on the eighth night and turn them on to fulfil the Misva. Rav Shlomo Zalman Auerbach and Rav Elyashiv agree with Hacham Bension’s Hidush.
Hacham Ovadia questions this leniency and rules that one should never make a Beracha on a flashlight. Moreover, if one did light with a flashlight and then had the opportunity to light with candles, he must do so and recite a Beracha. The Halacha is in accordance with Hacham Ovadia, because "Safek Berachot L’Hakel"-refrain from reciting Berachot when in doubt. Therefore, if a person has no way to light candles, for example when on a plane, he should turn on a battery powered flashlight without a Beracha.
----
Since the Misva is to light olive oil with a wick, Hacham Bension discusses whether one may light a wax covered wick, which is stuck though the floating cork disc. Is it a problem that the first moment of lighting is on the wax and not on the olive oil? Does this forfeit the advantage of using olive oil, since the moment of lighting is the execution of the Misva? Hacham Bension entertains the possibility of taking the wax off or dipping it in oil. However, he concluded that this is not necessary, since it burns off immediately and the primary source of the flame is oil.
----
On all nights of Chanukah one may use inferior wicks and oil for the actual Chanukah lights. Even if the flame flickers and does not catch well, there is no problem. On a weeknight there is no problem, since "Kavtah En Zakuk Lah"-if the candle is extinguished, he is not obligated to go back and relight it. Therefore, he does not have to be so careful to have a candle that lasts. Even on Shabbat, there is no concern that one may adjust a flickering wick. Since it is prohibited to derive benefit from the candle, he has no use for the flame and will not care if it flickers. However, on Shabbat, one must insure that for the Shamush candle he uses only superior wicks and oil that have a steady flame. The whole point of the Shamush is to have a candle from which to benefit, and therefore it must be a steady flame, so that he does not come to tamper with the flame on Shabbat. This is an interesting case in which the Shamush candle has more stringencies than the actual Misva candles.
SUMMARY
When it is not possible to light a candle, on may use a battery operated flashlight for Chanukah lighting, without a Beracha.
There is no problem using a wax-covered wick, even if one uses olive oil for his candles.
When lighting the Chanukah candles for Shabbat, the Shamush candle must have superior wicks and oil, even though the actual candles for the Misva do not.
