ScottG wrote:
Why not just calculate it when charging? Quick and easy.
Even I Remember That - A pictogram consisting of a capital "E" sitting on the crossbar of a capital "T", with a capital "I" to the left of the T's stem and a capital "R" to the right of the T's stem.
In the above pictogram put your finger over the "R" to find out how to calculate the Resistance of your RV battery. How you calculate it is take a look at what's remaining on the pictogram - what you see is the "E" sitting above the "I". ("E" represents voltage in the engineering world.)
To get the resistance of your RV battery ... while charging it, divide the amount of voltage ("E") on it's terminals by the amount of current ("I") flowing into it. In other words, resistance equals voltage divided by current.
The pictogram is a simple visual way to remember how to calculate any one of three things ... voltage(E), or current(I), or resistance(R) ... if you know the values of the other two things. A battery's internal resistance at a particular point in time and at a particular state of charge is a bit more complicated than this and there are more accurate/complex ways of measuring it, but getting into more detail is beyond necessity and the amount of coffee left in my cup at this time. :)
