Battery Cell Simulators

Battery cell simulators replace real battery cells with precisely controlled electronic channels and reproduce their electrical behavior under defined conditions. Each channel provides an adjustable cell voltage and, depending on the system, can source or absorb current. This enables safe, repeatable, and automated testing of battery management systems (BMS), cell monitoring systems (CMS), analog front ends (AFE), and charging electronics without using real batteries.

The ET System portfolio ranges from compact battery cell simulators with fewer than 10 channels to high-density multi-channel systems with more than 10 channels. Available solutions include unidirectional systems for standard supply tasks, bidirectional battery cell simulators for active balancing and charge/discharge simulation, and modular platforms for scalable BMS and hardware-in-the-loop (HIL) testing.

Typical applications include validating cell-voltage measurement, active and passive balancing, overvoltage and undervoltage detection, leakage-current behavior, communication, and safety functions. The appropriate battery cell simulator is selected according to channel count, voltage, current and power per channel, source and sink capability, isolation, accuracy, dynamic response, synchronization, fault-simulation functions, interfaces, and mechanical integration.

How to Select a Battery Cell Simulator

Selecting a suitable battery cell simulator starts with the electrical architecture of the battery management system and the number of cells that must be simulated. In addition to channel count, the required voltage, current, accuracy, source and sink capability, isolation, dynamic response, fault simulation, automation interfaces, and system scalability should be considered.

• Number of channels: Define how many battery cells must be simulated simultaneously. Compact systems with fewer than 10 channels are suitable for individual modules, development, and laboratory testing. Multi-channel battery cell simulators are designed for complete BMS, CMS, HIL, and production test systems.
• Channel isolation and series connection: Check whether every channel is galvanically isolated and whether the channels can be connected in series. Also verify the maximum permissible channel-to-channel, channel-to-ground, and total system voltage.
• Voltage, current, and power per channel: Define the required cell-voltage range, source current, sink current, and output power for every channel. Consider normal cell operation as well as balancing currents, overvoltage conditions, undervoltage conditions, and dynamic test profiles.
• Unidirectional or bidirectional operation: Unidirectional simulators supply current and are suitable when the BMS only measures the simulated cell voltage. Bidirectional battery cell simulators can source and absorb current and are required for active balancing, charging and discharging simulation, or DUTs that return energy to the simulator.
• Accuracy, resolution, and stability: Verify programming and measurement accuracy, voltage and current resolution, temperature drift, long-term stability, ripple, and noise. The required accuracy should be matched to the BMS measurement accuracy and diagnostic thresholds.
• Dynamic response and synchronization: Check voltage and current response times, settling behavior, update rate, sequence execution, and synchronization between channels. Fast synchronized changes are particularly important for HIL testing and dynamic battery profiles.
• Fault simulation: For BMS safety and diagnostic testing, determine which electrical faults must be simulated. Depending on the system, relevant functions may include open-wire conditions, short circuits, overvoltage, undervoltage, connection faults, temperature-sensor simulation, or complete pack-voltage simulation. Explore systems with integrated fault-simulation capabilities.
• SOC and battery-model simulation: Check whether state-of-charge (SOC), open-circuit-voltage curves, programmable internal resistance, charge and discharge profiles, or custom voltage sequences are required.
• Measurement functions: Depending on the application, integrated voltage and current measurement, leakage-current measurement, DVM channels, temperature acquisition, or external measurement modules may be required.
• Interfaces and automation: For automated test equipment (ATE) and HIL systems, verify remote-control commands, software compatibility, API or driver support, trigger and synchronization inputs, data logging, and available communication interfaces.
• Mechanical integration: Choose between a benchtop battery cell simulator, a compact multi-channel chassis, a system without a local display, or a modular 19-inch platform for integration into an automated test rack.
• Scalability: For systems with a changing number of cells, check whether additional channels, measurement modules, fault-insertion modules, temperature simulation, and pack-voltage simulation can be added later.
• Safety and cabling: Consider channel isolation, maximum system voltage, connector protection, interlocks, emergency shutdown, protection against reverse polarity, and suitable wiring for the required cell currents.

For application-specific BMS, CMS, HIL, and end-of-line test systems, ET System can combine battery cell simulators, measurement equipment, communication modules, fault insertion, safety technology, and control software through test system integration. For support with selecting a suitable configuration, contact our technical sales team.