I found a post about battery tester, and I noticed that the battery charge has a power that needs to be estimated in a slightly more complex way.
Could someone tell me where I could find an example code that can estimate what a person could complete when using a chart?
Take my case, with a 18650 battery, with 4.13V maximum voltage (no load) and 12.1A maximum current, measured with a multimeter (Victor VC97), we could have a false calculated power of 49.973 Watts. But in fact this battery was being used in a notebook, and the notebook was showing a power of approximately 26W. As the notebook battery consisted of 6x 18650 type batteries, we can estimate that each battery could supply only about 4.33 Watts.
Going back to our case, when plotting a graph, and delimiting the shear voltage at 3.7V, we can find an intersection point where the lines intersect. At this point we can note that for 3.7V the battery could only present 1.2A. And if we calculate 3.7V multiplied by 1.2V, we get 4.44 Watts. Which seems much more consistent with the result that the notebook was presenting.