NI Domestic Alternative: Battery Simulator for Rapid Simulation of 3C Product Battery Charging and Discharging Functions

Battery Simulator for 3C Product Testing: A Domestic Alternative to NI Hardware

Testing consumer electronics before the battery supply chain is ready is one of the most common bottlenecks in hardware development. Engineers who have worked in 3C product development — the shorthand for computers, communications, and consumer electronics — know the problem well: functional validation of charging and discharging circuits cannot wait for battery packs to arrive, and using real lithium cells during early bring-up introduces safety risks, variability between cells, and logistical overhead. A dedicated battery simulator solves all three problems by replacing the physical cell with a programmable voltage and current source that faithfully mimics the electrical behavior of a real battery.

This post introduces a domestically produced battery simulator series designed as a cost-effective alternative to NI (National Instruments) hardware for exactly this class of test application.

What Is a Battery Simulator?

A battery simulator is a bidirectional power supply that can source current (mimicking a discharging battery) and sink current (mimicking a charging battery) while holding the terminal voltage within a programmable window. The key word is bidirectional: conventional bench power supplies can only source, which means they cannot absorb regenerative current during a charge cycle. A true battery simulator must handle both directions with low output impedance and fast transient response so that the device under test sees something electrically close to a real cell.

Inside this product series, the bidirectional behavior is implemented with a DC-DC buck converter topology. Buck converters are well understood for their efficiency in step-down applications; the bidirectional variant adds a synchronous rectifier path so that energy can flow back from load to source, enabling current sinking. This avoids burning off regenerated energy as heat, which is important when cycling at higher power levels.

Three Form Factors for Different Power Scenarios

The simulator series ships in three hardware configurations, each matched to a different battery architecture commonly found in 3C products:

• 1S (single-cell dual-channel): Targets single-lithium-cell devices with two independent test channels per unit. Typical single-cell nominal voltage is 3.6 V–3.7 V, with full-charge cutoff around 4.2 V and discharge cutoff around 2.5 V–3.0 V depending on chemistry.
• 2S (dual-cell dual-channel): Covers two-cell series stacks, common in mid-range tablets and larger handhelds. Nominal stack voltage is roughly 7.2 V–7.4 V.
• 3S (triple-cell single-channel): Addresses higher-voltage stacks seen in laptops and power tools. A 3S lithium pack nominally sits around 10.8 V–11.1 V.

By offering dual-channel variants (1S and 2S), a single chassis can test two devices simultaneously, improving throughput in production line or qualification lab settings without doubling hardware cost.

Key Capability: Flexible Voltage and Current Programming

The adjustable voltage and current output is what makes these units genuinely useful for test. A real lithium cell has a state-of-charge-dependent voltage curve — it does not sit at a fixed voltage. A good battery simulator lets the engineer program that curve, or at minimum program any static operating point within the cell's voltage window, so the product firmware can be exercised across its entire input range. This is especially valuable for:

• Verifying low-battery cutoff thresholds in device firmware
• Characterizing charging IC behavior at different state-of-charge start points
• Stress-testing protection circuits at voltage extremes without the safety risk of overdriving a real cell

Leakage Detection

Beyond basic charge/discharge simulation, the series includes leakage current detection for 3C products. Leakage — small unintended current paths between the battery terminals and chassis ground or between PCB nodes — is a known root cause of field failures including battery drain, thermal events, and regulatory failures. Catching it at the bench stage, before boards are assembled into enclosures, is significantly cheaper than finding it in reliability testing or, worse, in the field. Having this detection integrated into the battery simulator means one instrument handles both power simulation and a critical safety check, reducing fixture complexity.

Positioning as a Domestic NI Alternative

National Instruments (now NI, part of Emerson) has long supplied battery simulator hardware to automotive, consumer electronics, and industrial test labs. The hardware is capable, but the cost and lead time of NI equipment can be prohibitive for smaller development shops or high-volume production environments where many parallel test stations are needed. This series is positioned explicitly as a domestic-market alternative — offering the core simulation and leakage-detection capabilities at a form factor and price point suited to 3C production and R&D workflows in the Chinese market, with local support and supply chain.

Practical Use Case: Battery-Free Stage Testing

The most direct application is enabling product testing before batteries are installed. In a typical hardware program, the battery pack and the main board may be on different procurement timelines. With a battery simulator standing in for the cell, firmware bring-up, charging IC validation, power management testing, and protection circuit verification can all proceed in parallel with battery supply chain activities. The simulator's programmed voltage and current limits replace the physical cell, and the device under test cannot distinguish the difference electrically. This compresses the schedule between first board spin and production readiness, which is often measured in weeks in competitive 3C product development cycles.