Cellwatch - Battery monitoring solutions

In the financial world, data centre downtime is simply not an option. In fact, the phrase "mission critical" may not be emphatic enough to describe how essential uptime is in this environment.

Considering how high the stakes are, financial concerns should be aware of and prevent the highest risk of failure in their backup power systems. Batteries are the weakest link! The risk of battery failure can be detected and the risk eliminated by daily battery monitoring.

Industry studies show the most common cause of data centre outages is a UPS battery failure, and the studies further show batteries are the highest risk of UPS failure. Batteries fail for many reasons; some in as little as two days. Even a new battery is a risk; 5% of new stationary batteries have been reported to fail in their warranty period. And it only takes one bad battery.

You can eliminate your most significant risk of outage, while reducing the cost with CELLWATCH battery monitoring.

Who uses Cellwatch

  • The largest internet-based retailers
  • The large telecommunications companies
  • Major power utility companies
  • The largest social media websites
  • Seven of the top ten US Banks rated in Fortune 500
  • One of the largest commercial aircraft manufacturers
  • Two of the top five global automakers
  • The largest aviation organisations
  • The second-largest media company
  • The world's largest stock exchanges
  • Nuclear power plants
  • Air traffic control across Europe and North America.

Cellwatch highlights

  • NDSL is a global company with worldwide deployment and support
  • 30 years of battery monitoring experience and innovation - Fifth-generation product!
  • Thousands of systems, monitoring more than a million monoblocs worldwide
  • Quality product with high MTBFs, designed to support many full battery life cycles
  • Pioneers of daily Ohmic Value monitoring, presents the health of each monobloc daily
  • Modular: three core components, easy to install and expand - Flexible and adaptable
  • Scalable 2-16V; VLA, VRLA, NiCad -any battery, any system, any size
  • Integrated Thermal Runaway Control; detects, warns and prevents
  • Designed for large data centres, campuses, and networks of data centre deployments
  • All auxiliary batteries on one system; entire site in one view - one page per screen view
  • Fibre-optics: noise immune and optically isolated
  • Easy to use and intuitive software - Access any data with three clicks
  • Accurate - no false positives, repeatable data.

Battery monitoring and alerts

Receive immediate alarm notification and view measurement data for more than 100,000 monoblocs. Cellwatch can measure:

  • Cell voltage
  • Cell ohmic value
  • Cell temperature
  • String temperature (ambient or pilot probes)
  • String voltage
  • Discharge alarms
  • Thermal runaway conditions
  • Ripple voltage.

Modular and scalable

Cellwatch addresses all critical batteries in the power network. It can be installed on new or old batteries, and the modular design allows the system to fit applications of any size and configuration, including monitoring many separate battery systems simultaneously - UPS, switchgear, generator, communications equipment.


Modular design allows for easy and cost-effective expansion or changes to your battery configuration. One system monitors all the monoblocs on site: 1.2V-16V; VLA, VRLA and NiCads.

Safe and reliable

  • Highest MTBFs and product availability in the industry
  • ICF 608.3 Compliant, meets UL 61010, supports IEEE 1188 and 1491
  • Reduces human contact with batteries.


Cellwatch is the only event-driven, battery monitor with a centralised, web-based management system. It gives you the power to consolidate your entire networked deployment -- building, campus or multi-campus -- into one command portal. You can quickly analyze battery performance across hundreds and thousands of monoblocs, or more, from a single screen.


Cellwatch fully integrates into third party Building Management Systems and DCIMs.

Detects, warns and prevents thermal runaway

Cellwatch detects thermal runaway conditions early and provides a warning period for customer action prior to isolating a string from the charger, as required by IFC and NFPA, to prevent thermal runaway from occurring.

Cost effective

  • Average ROI for Cellwatch is under three years; some systems in as little as six to nine months.
  • Negates the need for replacing batteries indiscriminately and allows for useful life extension of two plus years on average.


NDSL has consistently been a pioneer in our industry. Below are just a few of our "firsts":

  • First to build a fully modular battery monitoring system
  • First to introduce daily battery monitoring
  • First to provide a fibre-optic interconnect system
  • First to develop a self-addressable system
  • First to offer a noise immune solution
  • First to automate ohmic value settings
  • First to identify specific physical location of failures
  • First to introduce 'one-click' access to battery, string and cell information
  • First to introduce approved thermal runaway solution
  • First system to identify, warn and preclude thermal runaway
  • First ATEX compliant battery monitoring solution.

Contact Details

NDSL Limited,
Gloucester House,
399 Silbury Boulevard,
Milton Keynes MK9 2AH
United Kingdom
Contact: Esworth Hercules
+44 (0) 1908 303 735

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