A：The typical and easy method to calculate the battery SOC is to measure the battery voltage via an ADC and then mapping to the Look-up Table(LUT) to get the SOC value. Since the measured real-time voltage is variable due to the load and temperature change，it seldom equals the the battery open circuits voltage(OCV). Thus, the SOC calculated by this means is normally not accurate even the developer has an OCV and SOC LUT offered by battery vendors.
Cellwise fuel gauge measure the real-time battery voltage and temperature, which are as the input to the gauge algorithm. Another important input to the algorithm is the battery characterization data, which contains the modeling data of battery charge/discharge and impedance under different conditions. The developer should ship the battery sample to Cellwise for battery characterization and will get the battery profile. The final accurate SOC is calculated by Cellwise patented algorithm based on the real-time voltage, temperature and the battery profile. In common cases, the SOC error is limited within 3%.