Last winter I did a homebrew light setup. Powering two 20watt 12V MR16 bulbs in automotive housings off a 7AH 12V SLA battery. I received several complaints and saw people covering their eyes on the local MUP with one being aimed upwards and the other more downward.

I changed to a smaller battery and am using one 35watt bulb now, much less complaints when its aimed properly.