@ Zivo: Thank You for Your comment.

Yes, You are right. I use 4 cells of LifePO4. Actually in my case the max voltage went up to 12.8V (may be not the best battery) and I set the minimum to 10.7V as cut-off. (Can be 10V as well.)

I would sincerely appreciate, if You would share Your experience with ASC712.

To simplify the math, I thought the following:

Let say, I have the discharge curves only @C/10 from -10 to 50 Celsius .

(In this outdoor application the C/10 is the typical current consumption, on a long distance.)

It means, have to make 7x3 regressions. (I already made for 3 temperatures and may be from 30 Celsius to 50 Celsius will be the same. So only two more required).

Lat say, the rover running up & down. In every 30 minutes, I can adjust the speed for 1 minute to C/10 (let say to 1.2 A total current consumption for 12 Ah battery) and calculate the actual remaining capacity %.

This will not giving the best accuracy, but considering with temperature, which in this outdoor application is important.