reviving my 9 year old OEM battery?should i try

[racingbmwm3]

Of all the electrical loads, the resistive heater loads will be the biggest single draw, but your lights as a collective (fog, parking, tail, sidemarker, headlights) would be up there also.
I know with my wife's short commute during the winter, with the car full of kids, all 4 heated seats on high, all the lights on, windshield wipers on, front and rear heater fans blowing, the battery never really gets to recharge itself after starting in the morning. So, if we don't make any hour+ drives over the weekend, the trickle charger gets hooked up overnight.

FYI, your xenon's are about half the load of standard halogens.