So, Im wondering if anyone remembers their basic electronics, cuz im a little rusty. Here is what Im doing. I have a voltage sensor for my D-series FrSKY receiver. I have 2 goals here :

1. Light up an LED when the fuel tank is full (so I don't have to count turns or get fuel everywhere)
2. Send me an alert on the Transmitter when fuel is low.

I built everything the way I wanted and when I went to test....goal 1 failed miserably and goal 2 worked( barely) When I checked the readings I realized that I didnt take into consideration the resistance of the glow fuel itself. Im using a 7.4v 200mA Lipo to power the LED and I have 270ohm resistor inline (so I don't blow LED)...which I found out I don't need due to the massive about of resistance going through the fuel. My Voltmeter has a single Ohm setting with 1K max multiplier, and from what I could tell, there was about 200,000ohms of resistance in the fuel...but Id rather rely on the voltage sensor as I know very little about reading ohm meters and the connections were iffy as it was just testing. As I drained the fuel out, I noticed my voltage stepped down as I drained the fuel which was a pleasant surprise as I can use the data for a gauge with LUA scripts.

That being said...I need to know what Voltage and Amperage to send through this tank of fuel to generate 1.5v @ 20ma to light my LED. Right now Im seeing .5v passing through the nearly full tank...give or take .05v Some simple formulas Im sure, but I have had enough trial and error for 24 hours. Not sure if they have a battery that meets my needs, Any help would be appreciated it

Thanks so much