Abstract: A system for determining an accurate ohmic resistance value associated with a battery cell is provided. The system includes a microprocessor and a memory device. The memory device has a 3-D interpolation table with first, second, third, fourth, fifth, sixth, seventh, and eighth records, each having a respective SOC value, a respective temperature value, a respective current value, and a respective ohmic resistance value. The microprocessor performs a 3-D interpolation calculation based on a first SOC value, a first temperature value, and a first current value and each respective SOC value, each respective temperature value, and each respective current value in the records to determine the accurate ohmic resistance value associated with the battery cell.