SoC Measurement & Coulomb Counters

PowerTech Systems offers two types of coulomb meters :

– the “Soc-Monitor”: product communicating via RS232 or CAN Bus

– the “Coulomb-Counter”: this product measures the SOC of a battery and displays it on an integrated display. This product does not communicate externally.

Both products are based on the real-time current integration method described here.

“SOC-MONITOR” : High Precision Coulomb counter for industrial and embedded applications

The “SOC-monitor” product is a coulomb counting system for all types of lithium battery with voltages up to 60VDC. This product enables battery data to be communicated by wire (isolated CAN Bus or RS232).

It embeds a precision shunt (0.2 mΩ) which provides a better accuracy than Hall Effect sensors. This device can be used to measure voltage and current with a high precision and to estimate SOC (State of charge) of a battery with high accuracy.

All information (pack voltage, current, SOC) can be sent over 2 protocols of communication (2.5KV isolated CAN Bus or RS232 ) to an external controller. Parameters like battery nominal capacity can be set-up by sending a simple command to the device.

“SOC-Monitor” has very low residual power consumption in operation : 5.6mA with no communication.

The product includes a precision shunt resistor on the PCB for currents up to 100A. For higher currents, an external power shunt can be connected to measure up to several hundred amperes.

Product is shipped with a plastic protection case for easy commissioning.

“COULOMB-COUNTER” : High Precision Coulomb counter with display

CC 75/150/500 is a high precision Coulomb Counter device for monitoring the voltage (V), capacity (Ah), power (W) and energy of a battery. These information allow user to get a precise State of Charge in % (SoC) and Depth of Discharge (DoD) of the battery. It also calculates in real time remaining time before battery gets fully empty.

CC device has a memory feature to save SoC information when the device is powered off or accidentally disconnected.

CC 75/150/500 are suitable for lithium iron Phosphate (LiFePO4), Lithium ion and Li-Polymer batteries, lead acid and nickel metal hybrid batteries with a working voltage from 8V to 80V DC.

CC device exists in 3 versions:
CC75, measurement from 0 to 75A, compatible with M6 terminals
CC150, measurement from 0 to 150A, compatible with M8 terminals
CC500, measurement from 0 to 500A, compatible with M10 terminals