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Dave avatar image
Dave asked

VRM Charging Temperature VS. Battery Temperature DISPLAY

image-4-28-23-at-403-pm.jpgPlease see screenshot. When I log into my online VRM display under the "Charging" window there is a temperature that has a value which is often significantly different from the "Battery" window which is bringing data in from my thermometer installed inside the Rolls battery cell. It appears the temperature voltage compensation being applied by my Victron system is using the value inside the "Charging" window. this value is obviously incorrect when I make temp measurements. I need to know the difference between these two temperature values reported by VRM, how to eliminate the incorrect "Charging" window value and how to be sure the temperature based voltage adjustments being made by the Victron System are correct. Thanks or any help you can offer

temperature compensation
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pwfarnell answered ·

They should be the same, mine are. Have you set STS (share temperature sensor) properly.

Go to the settings menu, choose DVCC, set STS to on then select the correct temperature sensor for battery sensor.screenshot-20230429-094357-kindlephoto-893168754.png


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Dave avatar image
Dave answered ·
I have been using DVCC for almost a year with "Shared Temp Sens" on and the two temperature readings remained different. just last week I was forced to disable DVCC because my smart solar MPPT 250/100 charge controllers were flashing from Bulk right past Absorb straight to Float again and nothing I tried would allow the MPPT's actual absorb time, so I disabled the DVCC system and now the charge controllers are properly going through absorb again. even after disabling DVCC and share temp sens, I still have two very different temperature readings in the VRM. does anyone out there know what the heck this is about. and where the two different temp readings might come from? Now that I have disabled DVCC I am getting some bad readings in voltages in all of the cycles of charging, about .45 volts difference, usually. but this morning the voltages were spot on. it seems there should be something in the manual that explains where these voltage readings come from and which one the voltage compensation is reading.
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pwfarnell avatar image pwfarnell commented ·
The only other source of temp I know is the MPPT which has an internal temp sensor that it uses if no external sensor is used on the GX device, inverter or battery monitor as you probably know, could it be reverting to this. If you now have STS off try setting up a custom widget on one scale choose the MPPT battery temperature and the other the temperature sensor and see how they compare to the VRM value.

How is your battery temperature sensor hooked up. If it is on a Cerbo GX try another port.

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