BTECH Battery Ground Monitor

The BTECH Battery Ground Monitor detects dangerous battery to ground faults. Whether the fault is from a leaking battery or inadvertent bus connection to the battery rack, the BGM-500 detects the fault and reports an alarm. Battery system ground faults are a dangerous and potentially catastrophic DC plant condition that can cause unintended grounds to expose field service personnel to electric shock or ground fault conditions can lead to the battery system overheating and catastrophic failure.

Battery systems are not electrically connected to the cabinets or racks supporting them. The cabinets and rack are connected to Earth ground, if current is present on the ground cable then a ground fault exists. BTECH’s battery ground monitor system utilizes a precise, specialized custom current transducer to detect current leakage. The ground wire runs through the Current Transducer (CT), which is connected to the BGM-500, and the system continuously measures current flowing to ground. If the BGM-500 detects current above a configurable threshold value, it indicates a ground fault alarm. Depending on the alarm behavior configuration, the alarm either latches until cleared manually or clears when alarm conditions are corrected and ground current returns below alarm threshold value. Ground fault alarms can be triggered by positive or negative current, so the CT direction doesn’t affect the functionality of the BGM-500.

BTECH Battery Ground Monitor Specifications

BGM-500 Power Requirements

  • Power Input 1 1 0-240VAC-12VDC Output
  • (AC/DC Power Supply)
  • Max Current 1 A (5 Watts)

Measurement Capability

  • Measurement Range 0-500 mA DC
  • Measurement Uncertainty 1 .0% F.S.
  • CT Sensitivity 0.2% F.S.
  • CT Linearity 0.5% F.S.


  • USB (B)
  • Ethernet (RJ45 TCP/IP)
  • 1 NC/NO alarm relay


  • Operating Temperature 5-40°
  • Operating Humidity 0-80% – (non-condensing) for 0-30°C
  • 0-50% (non-condensing) for 31-40°C
  • Operating Altitude 0-2000 meters

BGM-500 Mounting

  • The BGM-500 can be mounted • ETL,CE Approved directly to the cabinet or rack
  • Wall-mounted inside a NEMA 1 enclosure
  • DIN rail mounted


  • BGM-500- H 4.12″xW 4.3″ x D 1.41″
  • Current Transducer
  • CT Sensor Size (packaging) – W2″x H3″x D1.25
  • CT Window Size: 5/8″

Modbus Settings

  • Device ID: 1
  • Address: 0001
  • (Coil Status) – set length to 16
  • Coil 1 : Ground Fault Alarm
  • Coil 2: Equipment error
  • Coil 1 5: Reset alarm
  • Coil 16: Watchdog
  • (Holding Register) – Set length to 2 – IEEE
  • 2 word floating point of current reading

For more information about BTECH,
call 800-876-9373 or email [email protected].