I went ahead and upgraded my Talon headlights to the way over priced Baja Design Squadron pro kit for the Talon. I was undecided between the sport or the pro, but after finally finding a couple of videos, I went with the pros. I also put a Vision X light bar up top. I did add an additional battery and dual volt meter to keep track of both batteries. When traveling @ 2000-3000 rpm the main battery shows 13.5 and the aux. battery shows 13 volts with all of the lights on. I think the light bar uses 210 watts and each of the 4 Squadron pro’s use 46 watts each. We will see this next week in the dunes how the batteries hold up and how much daylight they will produce. I have never been a fan of amber lights in the past, but got some covers to try. The Oregon dunes frequently get foggy at night, so I will put them to the test.
I see a couple things that pop out in your post. As I remember from your other posts, you are not running an isolator so your voltages should not be that different. You may want to check and see if the wires from the main battery to the second are sufficient. A minimum of 8 gauge should be used between the 2 batteries if the aux battery is in the front. Even if you are running a relay based isolator like the TruAM, your voltages should be similar when both batteries are charging, even with a large load like that.
Second, that is almost 400 watts just in lights (if they are all on at the same time) and probably a little more due to voltage drop in the wiring. The charging system is pretty big on the Talon (700 watts at 5000 RPM) but the running engine probably takes up around 250 watts. With all the lights on, you are pushing the charging system almost to its max. 13 on the aux battery is almost net charging (12.7 is fully charged for a lead acid battery) so it is barely keeping up at that point. Any more accessories may put you in a discharge state.
Nothing wrong with that as long as you are wired correctly and running a good isolator to make sure your main battery doesn't go dead. The other beauty of the isolator is you can always turn off something and allow the aux battery to recharge.