Ok guys. In my opinion, this "design" is getting too complicated. remember, we are trying to reduce the power supplied to a very unsophisticated electrical fuel gauge. As such, you don't need to clean up the power on the input or output side. The gauge wont care. The way I see it, the only reason you might have to put a capacitor on the output side is if the regulator oscillates to the point of not providing power at all (rapid on/off switching). But, many/most of the modern regulator don't require the capacitor (the 7806 family is typical of this).
Many of folks have used the 7806 regulator with good results even if the voltage is slightly less than a fully charged battery (not counting resistance losses in the normally less than ideal circuitry).
