to any1 that has done the ultimate light mod or is good in electronic

[Weapon-NZ]

ok this is for anyone that has done the ultimate light mod found on this page http://www.age.jp/~ex2/bit/01_custom_e.html or is good at electronic

anyways im planning to go buy some leds and do this mod, but one thing im trying to change is using an external battery source rather that used in the car, reason being i want my car's run time to be long, besides i plan to use hi intensity leds which the battery already found in the car wont power.

Im pretty new to electronics, infact i only started learning it at school this year, but im already pretty good with the soldering iron and positive that im capable of soldering the small bits found in the diagram, anyways does anyone know how to add a bigger battery into the diagram? im planning to use one of those button cells or maybe to so that it can power my led?

I was thinking of maybe adding the battery before the "vcc" OR disconnecting the wire leading from the vcc and conecting it to the grnd and in between that add my external battery. Would this idea work or would it give that power to the whole power circuit rather than just the "leds" part?