Battery Current Sensor Saved

This circuit is a series connection of two low-pass filters that measures current into and out of a battery. A difference amplifier measures the current through a shunt resistor. A summing junction amplifier provides a offset so both negative and positive currents can be measured with a uni-polar analog to digital converter. Simulation results illustrate a voltage proportional to the battery current and centered at the reference of 1.25 volts.