alright, so say I have a 7.4 V battery and I want to have a light come on when there is only 1 hour left of battery life. So I have to wire a 1 V LED to the main power supply? Right? wow, if so, that was easy.
oops! i read your post wrong1 i thought you were saying that you wanted an led to light up when the system was on. this is more difficult. daftmike has a tutorial somewhere.