Thailand’s energy authorities are already gaining practical experience with large-scale BESS. EGAT has deployed battery storage at several substations, including Bamnet Narong, Chai Badan and Mae Hong Son, where BESS is used for renewable energy integration, frequency regulation and improving grid stability. EGAT also states that the importance of BESS will increase as the share of renewable energy in Thailand’s power system grows.

The development of solar-plus-storage projects is also accelerating. In February 2026, the Asian Development Bank announced financing supporting two solar-plus-BESS projects in Thailand with a combined contracted capacity of 126 MW and 151 MWh of energy storage.

For Thailand, energy storage is therefore moving from a supporting technology toward an important part of the future power system.

But as BESS capacity increases, accurate and reliable current measurement becomes increasingly important.

Any deviation in current data may trigger battery over‑charging or over‑discharging. At best, this shortens battery service life; at worst, it may cause thermal runaway and lead to safety accidents. Hence, a precise “current heart” is of vital importance.

Featuring ultra‑convenient split‑core installation and accurate and reliable Hall‑effect measurement, the Acrel AHKC‑KA series split‑core Hall‑effect current sensors have become an indispensable core component for current monitoring in energy‑storage systems.

I. Why Do Energy‑Storage Systems Favor Split‑core Hall Sensors?

An energy‑storage system consists of hundreds of battery modules assembled into battery clusters through complex series‑parallel connections. Multiple battery clusters are then paralleled and connected to a PCS (Power Conversion System). Its current loops are characterised by high current, thick busbars and compact installation space.

During system integration or subsequent maintenance, conventional closed‑core sensors require disassembly of heavy copper busbars. This is not only time‑consuming and labour‑intensive but may also introduce hidden safety risks caused by poor electrical contact.

The split‑core design of the AHKC‑KA perfectly addresses this pain point. During installation, simply clip the two halves of the sensor onto the busbar and fasten the screws.

• For system integrators: Sensors can be fitted after cabling is completed, greatly improving assembly‑line efficiency.
• For maintenance personnel: Sensors can be replaced or calibrated on any branch circuit without shutting down the system, enabling genuine “hot‑swap” maintenance.

This “clip‑and‑use” capability brings great convenience for rapid deployment and flexible maintenance of energy‑storage systems.

II. Hall‑effect Principle: Accurate Measurement of Bidirectional High Current

Energy‑storage systems frequently switch between charging and discharging states, reversing current direction accordingly. Meanwhile, high‑frequency switching actions of the PCS generate substantial harmonics, resulting in current waveforms that are neither pure DC nor sinusoidal AC.

Built on the Hall‑effect principle, the AHKC‑KA is inherently capable of handling complex operating conditions:

• Bidirectional current measurement: It accurately measures positive‑ and negative‑direction currents, perfectly matching battery charge‑discharge cycles and delivering precise input for BMS (Battery Management System) SOC (State of Charge) estimation.
• Complex‑waveform capture: With a 0‑20 kHz wide bandwidth and ultra‑fast response time ≤ 5 μs, it faithfully reproduces current details during PCS switching. This enables the system to rapidly detect anomalies such as over‑current and short‑circuit, buying precious time for protective circuits.
• High linearity: Linearity ≤ 0.2 %FS guarantees full‑range measurement accuracy from low‑magnitude currents up to the rated maximum of 5 000 A, avoiding metering errors caused by non‑linearity.

III. Rugged Performance: Withstanding Extreme Thermal and Electromagnetic Conditions inside Energy‑Storage Containers

Energy‑storage containers operate in harsh environments: extremely high temperatures under summer solar exposure, severe cold in frigid northern regions, plus strong electromagnetic interference generated by working PCS units.

The AHKC‑KA series is engineered from the ground up to cope with these challenges:

• Wide operating temperature: Operating range of ‑40 ℃ ~ 85 ℃, ensuring stable performance in locations ranging from the Gobi Desert in Turpan to frigid forests in Northeast China.
• High dielectric strength: 2.5 kV / 50 Hz / 1 min electrical isolation fully separates the high‑voltage, high‑current battery side from the low‑voltage control circuits of BMS / PCS, protecting both equipment and personnel.
• Low‑power consumption: Total power consumption ≤ 0.5 W. Every watt of self‑loss matters for energy‑storage systems pursuing maximum energy efficiency.

IV. Typical Application Scenarios

• Total‑current monitoring for battery clusters: Installed on the positive or negative main circuit of a battery cluster to measure overall charge‑discharge current, providing core input for BMS main‑protection logic.
• Branch‑current monitoring for parallel battery clusters: In multi‑cluster parallel systems, fit one AHKC‑KA per branch to monitor current balance among branches and promptly identify poorly‑contacted or degraded battery clusters.
• DC‑side input monitoring for PCS: Mounted at the DC input terminals of the PCS to deliver accurate current feedback for PCS control algorithms, supporting efficient and stable energy conversion.