Trying to calculate the total capacity of my batteries, I wonder what is the calculation method used for SOC or DOD. Apparently for a particular period, I find a DOD (Wh out / nominal capacity) very different (5 times higher) from the DOD given by my management system (BMV712). What capacity value does it uses? What does the synchro do exactly with all these data?
DOD is calculated as entered battery capacity - (current and voltage adjusted for Peukert over time)
Common cause for discrepancy is connections to the battery negative instead of to the load side of the shunt.
Dont agree: should be (current and voltage adjusted for Peukert)/entered capacity. Your formula gives SOC.
But, If I divide (load as shown by VRM)/entered capacity I dont have the shown DOD !
VRM only reports values received from the system, here the BMV.
You don't say how big the discrepancy is or quote any values. Did you check for loads bypassing the BMV shunt?
No, apparently all OK. My problem is checking the remaining capacity of my old lead batteries. Computing SOC uses the nominal capacity which is most probably optimistic!
