All trademarks are the property of their respective owners.
A simple way to provide battery SOC in your product is through a static lookup table that correlates battery voltage to SOC. This lookup table can be generated by discharging the battery from full while measuring voltage and current.
The following steps must be taken to generate the voltage versus SOC table. This setup requires a voltmeter, ammeter, electronic load, and appropriate data logging equipment. Figure 2-1 shows a diagram of the test setup.
A C/10 value or less is ideal to minimize the effects of relaxation. Note this process takes a while (> 10 hours). There are more comments on this assumption in the Best Use Cases section.