BVS Series

The VHL is an integrated system that consists of - VHL Control Unit (VHL-CU) - Cell Voltage Module (CVM) - String Voltage Module (SVM) (optional) - String Current Module (SCM) (optional) The VHL-CU performs the monitoring and acquisition of measurement data from the CVM modules and its transfer to a PC. In addition, the VHL-CU provides the power supply to all connected CVM modules. The cell voltage modules are installed in the individual batteries (cells), performing both battery voltage and intercell voltage measurements. The VHL CM system acts as a complement to the Battery Charging Unit (BU) series of devices while performing a battery discharge test, providing detailed analysis of the condition of an individual cell. The VHL system identifies a possible battery malfunction by monitoring the following cell parameters from a set of CVM cell voltage modules: - The cell voltage - The inter-cell connection voltage In addition, the VHL-CU provides measurements of the ambient temperature at multiple locations (4 temperature channels).

General string voltage and current measurements can be achieved using the optional string voltage module (SVM) and string current module (SCM). The CVM modules detect cells that fail a discharge test based on the measured voltage values, so that these cells can be safely removed from the battery string. Data acquisition and extensive analysis capabilities of the data collected from the CVM are available in the Amperis application software package, which provides the user with comprehensive data visualisation, tracking and reporting.

Applications

• The list of instrument applications includes:
• Evaluation of the condition of the cells in real time by monitoring and recording cell voltages and CVM module array intercells during a battery capacity (discharge) test, as well as the charging procedure.
• Real-time room temperature monitoring with the VHL-CU
• Monitoring of string voltage and current using an additional string voltage module (SVM) and a string current module (SCM)
• In combination with the Battery Charging Unit (BU) instruments:
• Allows calculation of internal resistance according to IEC60896-21
• Detailed trend data and analysis provided by the Amperis software
• VHL CM connection diagram
• In the implementation of the VHL system, each CVM module is installed directly in an individual cell. The failure of one of the CVM modules will not affect the communication between the remains of operating the CVM modules and the VHL-CU. The diagram of the connection of the VHL to a battery chain is shown in the following figure.
• Connectivity diagram of the VHL system components in combination with the Battery Load Unit

Features and benefits

Extensive cell analysis during the discharge test

The use of the VHL as a complement to the Battery Charging Unit (BU) devices provides multiple advantages during a battery discharge test.

The CVM modules measure the voltage values in real time and send the recorded data to the control unit in user-defined intervals selected by the Amperis application software.

All out-of-tolerance measurement values are announced by an LED signal on an individual CVM module, so that failed cells can be detected before the entire battery system is compromised. This allows the failed cell to be safely detected and avoided during a discharge process.

The VHL-CU has up to 4 channels for measuring the ambient temperature in multiple locations. Two additional modules can be used in case voltage and current measurements of the chain are required. The use of these two optional modules allows the VHL system to work in conjunction with any load bank on the market and perform a fully automated capacity test.

Measurement of the internal resistance of the battery

The calculation of the internal resistance of the battery is an additional feature of the VHL available in combination with the SSB instruments. The test method used for the calculation of the internal resistance complies with the battery test methods recommended by IEC60896-21.

Amperis Software

All results transferred from the VHL system can be viewed, analysed and presented in selectable report forms using the Amperis software application.

Data can be transferred to a PC via USB or Bluetooth communication.

Both the VHL and the SSB device provided results that can be seen in the same report form. A quick pass/fail test of the internal resistance values of a cell can be performed according to user-defined thresholds, adding additional information on the status of an individual cell.

Main features of Amperis Software

• Total control of the VHL from a PC
• The results of the SSB device discharge and the CVM cell voltage values can be viewed in a software file.
• Acquisition and detailed analysis of measured data
• String voltage, cell voltage, intercell voltage and internal resistance trend
• SSB and VHL test reports are available in various formats (Excel spreadsheet, pdf, word or RTF)
• User-selected sampling time of the CVM