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measure percentage

Hello everyone! I'm doing on our project on labview. We are using a battery and need to measure the percentage of power that the battery left. As the power used, the voltage will also decrease. Here is a table of the relationship between voltage and percentage. Can anyone help me to get the vary value of percentage? Thanks!table.JPG

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Message 1 of 43

Are you having a problem with LabVIEW problem or a problem with math? What have you tried so far?

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Message 2 of 43

Both the problems...How to get the formula of the table? Then how to program on labview?

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Message 3 of 43

So what you mean here is, you want to display the exact percentage of battery depending on the voltage (Suppost 11.23 V mean 54% like that)? You can do a Linear fit ( with the Voltage as Y values and Percentage as X values (Or may be the other way) and find the Slope and Intercept. Then with the voltage reading Mulitply the slope and Add the intercept, you are done.


The best solution is the one you find it by yourself
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Message 4 of 43

Create an array of points (cluster of xy pairs, x=voltage, y=%), then use interpolate array with the given voltage.

LabVIEW Champion. It all comes together in GCentral GCentral
What does "Engineering Redefined" mean??
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Message 5 of 43

Actually it is not a linear one...

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Message 6 of 43

Maybe a curve.

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Message 7 of 43

Hi xuan,


either use Altenbach's suggestion (with linear interpolation between your data points) or calculate a polynomial regression of your choice. Then use PolynomialEvaluation function to calc battery state from voltage…

Best regards,

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
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Message 8 of 43

Using a lookup table as Altenbach suggested is the easiest way to go.

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Message 9 of 43

I'm sorry...Can u give me a more detailed solution?

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Message 10 of 43