Automotive Battery Monitoring System

A growing trend in modern car design is the increasing use of the primary automotive battery for purposes other than starting the engine. In conventional vehicle designs, batteries are tasked with supporting ever-increasing key-off loads and providing large amounts of supplemental energy when vehicle demands exceed alternator output.

More recently, environmental and fuel economy concerns are driving the development of start / stop, light hybrid platforms that further increase reliance on the car battery as an auxilliary energy source.

As a result, modern car batteries are increasingly in situations of heavy discharge as part of normal vehicle operation. In order to avoid cranking failure, and to maintain overall vehicle reliability, battery monitoring systems must provide highly accurate state of charge and state of health information to the vehicle control and diagnostic computers.

In response to these needs, Argus developed CrankCheck� and Dual Large Pulse Resistance� (DLPR) technologies. These two revolutionary technologies are condensed into a very small, ruggedized sensor package for OE integration in vehicles. The system provides SOC and SOH as well as other critical battery data directly to the vehicle information network.

Key benefits include:

State of health and state of charge information exceeding the accuracy of traditional VIT (shunt, coulomb counting) sensor technology.
Self learning algorithms avoid the need for battery specific programming, allowing the system to seamlessly adapt to a wide range of OE and aftermarket batteries, including flooded, maintenance free, AGM.
Sensor directly outputs SoC% and SoH%, and a wide range of other basic and derived battery performance attributes. No vehicle level processing of V,I,T data is required.
Revolutionary Dual Large Pulse Resistance (DLPR) technology enables consistently accurate, real-time, state of health, and state of charge, 'fuel gauge' information.
Factory diagnostics mode identifies defective batteries immediately upon battery installation during vehicle assembly.
Critical battery health metrics can be discovered through OBD system
Industry leading cost, performance, and sensor size

Argus is working with auto manufacturers, tier one system suppliers, and military organizations and suppliers globally to integrate the Argus Automotive Battery Monitoring Systems into new vehicle platforms. For more information about the Argus ABMS, please contact our sensor sales group.

Functional Description

Physical

The ABMS consists of a small over-molded sensor electronics package designed to be integrated into the negative or positive battery harness cable near the terminal end. The sensor package connects in parallel (no series shunt needed) to the battery harness terminal clamps and includes a customer defined data port (CAN, LIN, serial, or other proprietary) to support communication with the vehicle system.

Typical sensor package size excluding sensor leads is approximately 11 cm3.

Operational

The test technology is based on Argus' patented Large Pulse Resistance (LPR) technology with an enhancement that further improves accuracy in dynamic environments.

LPR technology powers Argus' line of diagnostic battery test equipment to identify all defects effecting battery performance, including: sulfation, stratification, dehydration, corrosion, grid swelling, loss of material, short circuits, and lead fractures.

The sensor module uses Dual Large Pulse Resistance (DLPR) to actively measure internal resistance of the battery in real time, regardless of battery duty cycle. Test frequency is nominally every 60 seconds, and is automatically scaled based on battery activity.

Embedded software running within the Argus sensor package converts real time internal resistance, voltage and temperature data into State of Charge, State of Health, and a wide range of other battery performance (state of function) values.

Sensors can easily be programmed to support vehicle and platform specific needs, or they may be implemented in 'self configure' mode where a single sensor can be installed in range of vehicles using a range of OE and aftermarket batteries, eliminating the need for custom programming at the sensor level and avoiding the need for custom battery monitoring application logic running at the vehicle level.

Specifications

All ABMS systems are customized to meet the needs of each OE customer. The following are example lists of data provided by the ABMS system

The following basic parameters can be provided during all points of the battery duty cycle:

Battery Voltage
Battery Temperature (based on probe location)
Battery internal resistance
Current, charge/discharge (requires optional current sensor)
Battery State of Charge
Battery available energy
Battery effective reserve capacity
Battery State of Health (effective reserve capacity compared to new)
Cranking State of Health (if CrankCheck is enabled)
Time to empty (requires optional current sensor)
Discharge cycle count
Average depth of discharge

Any values or warning conditions, derived from the above parameters may also be included in the software based on OE requirement, such as user warnings or operational thresholds. For example:

Charge battery soon
Charge battery now
Stop charge
Replace soon
End of life, replace now
Battery failure, replace now
Hybrid crank enable
Hybrid stop authorization