Eagle Eye Power Solutions

Your VIGILANT™ and ELM Sensors

When the electrolyte level goes below the limit, the ELM sensor will detect this and its LED will turn red. Upon detecting a low level, the VIGILANT will automatically reset the ELM sensor 3 times. If after the third time, the ELM is still registering a low level, the VIGILANT monitor will generate an alarm and its LED will turn red.

This is done so that if there are any transient issues with the electrolyte level detection (such as being put under heavy charge, causing the electrolyte in the battery to become agitated) then the VIGILANT monitor will not alarm and unnecessarily cause a site visit.

Temperature levels, however, will immediately alarm upon detection.

When you have topped up a Unit’s electrolyte, you need to reset the ELM so that it can return to its normal detection operation. There are two ways to do this.

Using the VIGILANT Web UI

Screenshot video overview of user interaction with Vigilant Web UI

It is simple to reset the ELM sensor from the VIGILANT Web Interface. Navigate to the Cells/Units screen, click on the cell/unit that has an alarmed ELM sensor (in the case of the above video, it’s #8). If the cell/unit has an attached ELM, the “Reset ELM” button will appear. Click that button, and the VIGILANT will schedule for the ELM to be reset.

Not using the VIGILANT Web UI

It is also possible to reset an ELM without connecting to the VIGILANT web UI. There is a small, circular button at the top right of the ELM. A quick press of this button will reset the ELM. The red light will go out, and the “No Fault” light will briefly blink before becoming solidly green.

See the ELM manual for more information about the operation of this button.

Close-up photo of Vigilant battery monitoring sensor


When the ELM sensor is reset, it can take (up to) 90 minutes for the VIGILANT to be satisfied that the electrolyte has returned to acceptable levels. At this point, the VIGILANT ELM alarm will be deactivated and the monitor LED will switch back to green.

For more information on the VIGILANT and ELM, click the product links below:

VIGILANT Next Generation Battery Monitoring

ELM-Series Electrolyte Level Monitoring

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