VM-100 Battery Voltage Monitor

Model # VM-100

The Eagle Eye VM-100 Battery Voltage Monitor is a simplistic & inexpensive battery monitoring system designed to monitor battery string voltage for over and under voltage conditions. The VM-100 Battery Voltage Monitor is used in 24V, 48V, 125V, and 250V applications - and reads battery bus status, detects out-of-limit conditions, and provides alarm indications per-user settings. The unit is equipped with four (4) Form C Contacts - Two (2) Form C contacts for over voltage & Two (2) Form C contacts for under voltage. Modbus protocol output is also available on all units.

Designed with a color touchscreen, the VM-100 Battery Voltage Monitor has a user-friendly interface that displays the monitor's status, under voltage and over voltage trip values, time delay, and IP address settings. When the VM-100 is installed & power is applied to the battery voltage monitor, the firmware reads the stored settings and begins monitoring. Changing the stored settings, including the over and under voltage parameters & the monitor's IP address is done on the VM-100 color touchscreen. If over or under voltage is detected, the voltage status will appear and the VM-100 can activate a Form C contact. Installation of the VM-100 Battery Voltage Monitor is simple - it can be installed as a wall, panel, or DIN rail unit, and includes a mounting kit for DIN rail or wall mounts.

Monitoring for battery string voltage will provide critical battery cell protection and ensure the longevity of the battery system. Overvoltage can lead to overcharging and overheating of the batteries, which can cause irreversible cell destruction. Under voltage will also cause irreversible battery damage if left uncorrected. Measuring battery voltage with the VM-100 will allow the user to determine how charged their batteries are, and allow for immediate corrective action if needed.

The VM-100 Battery Voltage Monitor includes:

  • VM-100 unit (for 24V, 48V, 125V or 250V)
  • DIN rail mounting clip
  • Backplate for wall mounting
  • User Manual

The VM-100 is one of a family of digital monitors that read offset voltage from ground and alarms for ground faults. Eagle Eye offers the GFM-100 Ground Fault Monitor to monitor battery ground faults. Eagle Eye also offers the VGM-100 which combines the functions of the GFM-100 Ground Fault Monitor & the VM-100 Voltage Monitor into a single unit - allowing monitoring for both battery string voltage and ground faults simultaneously.

  • Specifications
  • FAQs
  • Benefits

Technical Specs

Measurement Range:Battery Voltage: 18-32, 38-60, 90-160, 180-320 VDC
Fault Resistance Limit Set: 1 – 100 kOhm
Output Contacts:(4) Form C
Contact Rating:125 VAC/VDC: 0.5A
30VDC: 2A
Maximum Switching Power:60 W
Power Requirements:Powered by connected battery DC voltage
Noise Immunity:IEEE/ANSI Standard C 37.90a-1989 compliance
Time Delay to Alarm:Adjustable 1 – 999 seconds
Operating Environment:Temp: 0 – 55°C (32 – 131°F), Humidity: 0 – 95% RH
Dimensions / Weight:147 x 91 x 45 mm (5.77 x 3.56 x 1.77 in) / 284 g (10 oz)


What are some common applications areas for this product?
Common applications include but are not limited to:

  • Power Utilities
  • Telecommunications
  • CATV / Broadband
  • Mission Critical Facilities
  • UPS Systems
  • Power Generation & Distribution
  • Financial Institutions
  • Oil, Gas & Fuel & Petrochemical Operations
  • Mining
  • Government/Defense
  • Transportation Operations
  • Hospitals
  • Emergency Lighting
  • Green Energy
  • Call Centers
  • Battery Suppliers and Manufacturers
  • Battery Service Groups
  • Medical/Biotechnology

What is are the contact ratings for the Form C contacts?
The relays have a contact rating of 60W, with a maximum voltage rating of 220VDC, and a maximum current rating of 2A. With these ratings, this relay can switch 2A at 30VDC or less, 0.5A at 125VDC, but only 0.009A at 220 VDC. An external relay would be needed if the customer wanted to increase the rating past the limit.

Do the connections between the monitor and the batteries need to be fused?
No, the monitor has a built in fuse to protect the monitor. However, you may want to fuse the connections to protect against the possibility of a short circuit occurring in the wiring to the monitor.

Is the VM-100 Battery Voltage Monitor CSA certified?
The VM-100 is CE certified. For Canadian customers, CSA certification is not required on DC powered units. Please contact Eagle Eye with any questions on certification requirements.


  • Color touchscreen simple interface
  • Ethernet connectivity to web interface or Modbus protocol
  • (4) Form C Contacts
  • High reliability & durability
  • Simple installation with mounting kit for DIN rail or wall mount
  • Monitors Voltage in 24V, 48V, 125V, & 250V batteries
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  • Model #

    Battery Voltage Monitor, available for 24V, 48V, 125V, or 250V

    Determine part number for required voltage, Ex. VM-100-XXX would be VM-100-48 for 48V applications.

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Eagle Eye Power Solutions Battery Monitoring Overview

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Companies We Serve
  • Battery Monitoring: Voltage: American Electric PowerAmeren Energy: Battery Voltage Monitoring
  • Duke Energy: Battery Monitoring for VoltageATT: Battery Voltage Monitor
  • OG&E: Battery Monitoring for VoltageDuke Energy: Voltage Monitoring