question

As an afterthought, one way to address this, as well as the issue that tanks often have various shapes, i.e. taper towards the bottom, would be to have a third way of entering tank types, where one could input the resistance for various percentages of filling, I.e in my case, a full tank would be 82 ohm, empty would be 0, and have some points in betweeen, and the VGX could calculate the level based on this. Victron, anything for you to consider?

I have the same issue - various two tanks that are not uniform in their profile. (#1) Bottom has largest volume with four 'steps' to full with the smallest volume. As with some 'heavy truck' fuel tanks the 'steps' are built in as the treads. (#2) a variation on the above really with a sloping side to cater for the hull changes. Still trying to figure that out.

On my boat, I have a Venus GX, and I thought it would be nifty to use it to survey the tanks (1 fuel, 2 water) as well. There are already tank meters on the tanks, which are hooked up to a shared analog gauge. I have measured the fuel tank meter, which shows 180 ohm when the tank is full. However, there is a resistor of sorts on the gauge, which shows about 150 ohm, hence the combined resistance is 82 ohm. Consequently, when hooking up the VGX to this setup, it says that the tank is about 45% full.

The obvious fix would be to disconnect the analog gauge, but I would certainly prefer to keep it as well. Is there a way to resolve this?

Hi Erik,

I emailed Victron tech support and they stated that it would not work. The tank level inputs are supplied with 5 volts and the analog gauge is supplied with 12V via a bridge circuit through the ignition switch.

I am trying to do exactly the same thing ie. keep my analog gauge and and use the Venus GX to monitor the tank level. The resistor on your analog gauge is basically a matching resistor so the analog gauge can be used for varying range resistor level sensors. ie 0-180ohm or my 240 to 30ohm sensor. (This is done by using a different resistor value)

I am sure there is something out on the market that can be purchased ie an analog to digital (AD) - digital to analog (DAC) combo unit. It is just a matter of finding something as who wants to go through the hassle of building your own circuit.

I know it is possible but it may be more of a hassle then its worth.

Jason

Hey Michael

I found a device that has what you are talking about and will work. Yacht Devices YDTA-01 will work in unison with a resistive sensor and an analog gauge (has a 12 point calibration) but converts it to a NMEA 2000 protocol standard which means that using the Venus GX may be out of the question. You may have to implement a NMEA bus system if you don't have one in place. I think I may be pursing that path.