Marcell MAR500A Cellular Freeze Temperature and Power Monitor
Freeze Alarm

Marcell MAR500A Cellular Power, Temperature, Freeze Alarm

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  • Description

    Marcell MAR500A Cellular Freeze Alarm

    Cellular communication - No telephone line or Internet required!

    The MarCell MAR-500A is a cellular based monitoring device that monitors for low or high temperatures, freezing, humidity and power failures where a phone line or Internet connection isn't practical or available.  The MAR500 is perfect for monitoring homes, condos, cottages, RVs, remote properties, AirBNB rentals or businesses. 

    When power fails or the temperature or humidity rises or falls outside your normal range, you can receive an email, SMS text message or call right away!

    In addition to reporting in case of a problem, the cellular freeze alarm communicates to the Sensored Life cloud service, where users can check status, program the alarm points, add or remove alert users/contacts.  Communication is via the Verizon cellular network and can be sent to any device that can receive an SMS text message or email or voice phone call.

    In case of a power failure, the on board battery keeps it working so alerts can still be sent. 

    Water & flood sensors (Water Spuck) can be purchased here:


    Please note:  Marcell requires a subscription service which starts at 8.25 per month and can be stopped and started as needed.


    Marcell MAR500A Features:

    • No Phone Line or Internet required at monitored location
    • Monitor for hi and low temperature and freezing
    • Monitor for power failures
    • Monitor for hi and low humidity
    • Will send alerts via text, email, and telephone calls.
    • Uses Verizon network to connect to the Sensored Life cloud service



    How often does Marcell report in with temperature and humidity data?

    Current temperature and humidity is checked against your settings every 10 seconds. If the current readings are outside of your “safe range”, an alert will be sent immediately. If readings are within your safe range, they are recorded every hour locally and uploaded every 6 to 8 hours to the cloud service for historical logging.  At that point, this data is displayed on the web site in graph or chart form.

    In case of an alarm condition, the alert is sent right away!

    A subscription is required to monitor the property and receive alarm notifications. Service subscriptions are available on a month-to-month, seasonal or annual basis via starting at USD$8.25/mo.

    How does the cellular billing work?

    Part of the beauty of the MAR-500A is that you can turn the cellular connection on and off on a monthly basis so you are only paying for the coverage you need when you need it. You can do this online at any time - quickly, easily and with no hassle.  Billing plans are available starting at USD$8.25 per month.  Note that Marcell uses the Verizon network and requires a decent cellular signal at the installation location.  Works in continental USA only.

    Also known as Homesitter part# HS-500SL

    MarCell Cellular Freeze Alarm Details

    • Power: 110VAC to 5VDC, 2A plug-in power adapter with built-in battery backup
    • Temperature Alarm Range: 20 to 120F (-7 to 49C)
    • Humidity Alarm Range: 10 to 90% RH
    • Operating Temperature Limits: 20 to 158F (-7 to 70C)
    • Rechargeable Battery: Internal 3.7V 800mAh Li-ion rechargeable


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    SKU: MAR500A
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