250-500cc Changing the wiring on the duel sport setup

Hey guys, got a plate on y wr300 along with one of those tusk duel sport kits that has a battery that runs led lights. Well what I have discovered is a couple times I forgot to charge the battery and lights went dim or just didnt work cus I forgot and left the switch on overnight. So....I was just thinking of tappping into the system and using one of these for the led's as to not blow out the bulbs.
http://www.trailtech.net/7004-RR150.html

Theres a yellow and black wire going to the back not connected to anything. I assume its for the rear tail lights. I was gonna just tap into that.

This way the plan is that whenever the bike is running all lights/blinkers and horn would be on.

Will this work? Any issues or things I should/shouldnt do?

It can work like that. I had my 300 set up similar to that last year when I was dual sporting it, but I used the OE regulator with out a battery and just ran it off AC.

To go with AC and DC you will have to have the DC stuff running of a separate ground wire that's common to the DC circuit and isolated from the AC. With the total AC system I could just ground to the frame.