Q) How early am I allowed to light Shabbos candles on Erev Shabbos? Also, can I light and then drive elsewhere for davening?
A) There are three halachic issues that need to be discussed: (1) the earliest time for Shabbos acceptance, (2) lighting Shabbos candles without accepting Shabbos and (3) the issue of bal yakdim.
(1) The earliest time that it is possible to accept Shabbos is plag hamincha (i.e. 1¼ relative hours before the end of the day – Shulchan Aruch OC 263:4). Shabbos acceptance before plag hamincha has no effect; and consequently one is still permitted to perform melochos (Mishna Berura Siman 263 s.k. 18).
(2) Regarding lighting candles without accepting Shabbos, we find various opinions about this in the Rishonim (quoted by the Tur OC 263):
• The Behag opines that Shabbos candle lighting is considered an automatic acceptance of Shabbos.
• According to Tosfos, Shabbos acceptance is independent of candle lighting.
• The Maharam and Mordechai opine that it is possible to stipulate prior to lighting that one is not intending to accept Shabbos through candle lighting.
• The Kolbo quotes an opinion that one is not able to stipulate that one is not accepting Shabbos by lighting Shabbos candles; and even if one did stipulate, the stipulation has no effect and Shabbos is automatically accepted.
The Shulchan Aruch (OC 263:10) quotes all four opinions (without giving a clear ruling), and the Remo (ibid) comments that the custom is that a lady who is lighting automatically accepts Shabbos by lighting – unless she stipulates prior to lighting that she does not wish to accept Shabbos through lighting. [The Remo also adds that even an unspoken stipulation – i.e. that one has in mind not to accept Shabbos – is effective.]
The Mishna Berura (s.k. 44 based on the Magen Avrohom) adds that one should only stipulate in a case of necessity – since there are opinions who maintain that a stipulation does not have any effect.
(3) Lastly, bal yakdim is the restriction of accepting Shabbos early (i.e earlier than the regular lighting time, but after plag hamincha) without accepting Shabbos at the time of lighting (Shulchan Aruch OC 263:4).
The Mishna Berura rules that bal yakdim is a prohibition l’chatchilo. B’dieved, one has been yotze and need not light Shabbos candles again.
We do not find in the Poskim clear parameters as to the exact time of bal yakdim. It appears that if one lights at a time that is significantly earlier than the standard lighting time of his location, this is included in bal yakdim and should ideally be avoided.