Development of battery diagnostic for commercial vehicles using onboard battery sensor

In this thesis it will be shown the usage and the exploitation of a battery sensor, already used by Iveco onboard of the vehicles, with a diagnosis purpose. The strength of this approach is the possibility to take advantage of something already present onboard of the vehicle, but also the possibility to have an historical trend of the measurement and of the states of the battery. In addition, the standard among the dealers of truck makers offers often wrong measurements leading to a wrong replacement of the batteries, so a change in the method of the diagnosis is required. The proposed method consists in the usage of an Intelligent Battery Sensor (IBS) that continuously estimates SOC, SOH and the internal resistance value, and measures the temperature, the voltages and the battery current. Together with the IBS also a Universal Diagnosis Tool (UDT) is developed, which, once connected to the On Board Diagnostic (OBD) port of the vehicle, can retrieve the data coming from the sensor and, on the base of them, estimates another value of SOH and returns a diagnosis on the batteries. To state the reliability of the measurements performed and to choose between the two computed values of SOH, are introduced some thresholds to identify the quality level of the measurement. The final output of the UDT, in addition to the state of the battery, can be: •??Battery OK: no necessity to substitute the battery; •??Battery 1 KO: necessity to substitute the battery 1; •??Battery 2 KO: necessity to substitute the battery 2; •??Batteries to be charged: recharge the batteries then perform again the measure; •??Measure again: something during the process went wrong so the process must be repeated; After the proposal of the method and the analysis of the architecture of the system inside the vehicle, two different testing campaign are done: the first one has the purpose to characterize the performances of the batteries in terms of residual capacity and ability to perform the cold cranking current as defined by the proper norm; the second test campaign has the scope to build a database that relates SOC, temperature, SOH and internal resistance value for the computation of the SOH inside the UDT. The validation of the tool has been considered impossible due to the company restriction caused by the spreading of the SARS-COV2 virus, but a validation test procedure is proposed and some comparison between the UDT and the shelf tool that nowadays is the standard for the garages to check the batteries status are done.