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How Battery Monitoring Retains Profits

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This article brought to you by: Data Power Monitoring Corporation

We have been monitoring UPS and other batteries for over 10 years and have collected data on many individual batteries. Our business addresses:

  • Dozens of multi-national enterprise and data center customers

  • Hundreds of monitors deployed in both single and multi-site installations

  • Thousands of battery cells/jars being remotely monitored and tracked

These are in our database and consist of batteries made by several manufacturers of both Valve Regulated Lead Acid (VRLA) batteries--also known as “sealed” or “Maintenance Free”--and Vented batteries--also known as “Flooded” or “Wet." 

Since we monitor many of these batteries under our “Remote Polling Contracts,” it is important that we collect data on a weekly basis, archive those data in a database, and analyze them. We also collect valuable logging data, during emergency outages or during planned load tests. By examining voltage or Ohmic exceptions and trends, we are able to warn our customers of impeding problems. We will briefly tell you what we have learned so far.

Manual Battery Maintenance

Physical battery maintenance is proven, is defined by IEEE standards, and goes a long way towards establishing battery health at the time of the maintenance action.  Let's look at some of the things involved with this important maintenance process.

Typical PM (preventative maintenance actions) include accurately checking and recording battery voltages. In addition, you need to do connection resistance checks with an accurate micro-ohm meter. Periodically, you must check all connections and repair as needed.

In Flooded or vented batteries, you need to check the Specific Gravity for each cell. While doing that, you perform a visual examination--which can reveal quite a bit of important information. Good maintenance includes accurate checking of Ohmic values with instruments designed specifically for that purpose.

Load tests are the "gold standard" measurement of a battery system’s health (but only at the time of the load test).  While doing a load test, you must log individual cell or jar voltage readings several times to determine individual unit health. You should do this test per IEEE recommended standards and practices (IEEE 1188 for VRLA, and IEEE 450 for Vented). These standards do have their weaknesses, but don't deviate from them without considerable research into what you are doing.

Remote Surveillance

As an enhancement to physical battery preventative and corrective maintenance, remote battery surveillance keeps the battery user informed and enhances prediction. This helps ensure you'll have a healthy battery system that is ready to perform on demand. 

A good system will record voltages typically one week apart to two decimal point accuracy. You can change the interval frequency, if the situation dictates.

A good system will record Ohmic values checks are made and recorded typically at one-week intervals. You can change the interval frequency, if the situation dictates. Interconnect Ohmic values are typically a component within the Ohmic check process.  Simple diagnostic procedures determine Ohmic exceptions or changes relating to the battery or to the connections.

The system should check ambient and battery temperatures each minute for unacceptable differences (usually 15 degrees F or greater) and for unacceptably high or low temperatures.

The system must log hits (discharges) with time, date, and duration. Hit information, including discharge scan data, is always logged. Whoever performs your remote monitoring should have the ability to analyze all collected data with a combination of intelligent software and the judgment of trained and experienced battery monitoring experts.  


Battery Voltage trends are important tool to predictive analysis, especially true with respect to wet cells. However, we have learned that Ohmic trends tell us a lot more and give us more early warning--regardless of battery type. This is particularly true when connections start corroding or giving up, or internal battery mechanisms are showing signs of failure. 

Regardless of voltage and Ohmic value exceptions or trends, the true and tried discharge test will get us from 90% predictive data to 100% (at the time of the discharge test). Remember, the load test is costly to the unit--it's a destructive test that leaves the battery with less capacity than it had before the test. The other tests are not destructive, and they enable you to apply the load test when it is truly merited. 

Interesting Factoid

In our experience, based on collected data, we find that over 90% of VRLA failure indications are due to the battery itself. The inverse is true for Flooded or Vented product. 

Why Remote Monitoring?

Sophisticated remote monitoring software eliminates the need for copious manual records, and provides other advantages. Yet, there's a problem here. Why, for example, did a data center with such a system not see an impending failure before it happened? They had a top notch system, but they were caught completely by surprise when their batteries didn't provide sufficient backup for a power loss. Nobody was watching the monitoring system!

Like any other monitoring system, the investment is worthless unless qualified individuals watch and interprets the information. Outsourced battery monitoring specialists can determine battery state of health quickly and can predict future problems, which require maintenance and/or replacement. Example: Rather that replace a whole string of batteries, you can replace individual units--thus extending the useful life of the battery string. Typically, when 20% or so of battery units have been replaced, it is time to consider a new battery string due to unacceptable battery capacity variances within the string. In addition, you can see aging trends of the whole battery system, and recommendations can be made regarding battery string replacements in time to prevent a failure. 

You can enhance many manual tasks by outsourcing remote monitoring. You can do the preventive maintenance when you need to, rather than by an arbitrary calendar. This saves time and materials. Service organizations using these methods can cut battery maintenance costs. Facility managers who oversee such testing over multiple locations can reduce “windshield time." 

Remote Battery Monitoring should be done by experts, who have proper training and experience for this task.  This significantly cuts back on user training in specialized maintenance and interpretation tasks. 

Four Points to Remember 

  1. Battery monitoring equipment is only as effective as the people who interpret the data or information provided by that equipment.

  2. When evaluating battery monitoring, consider the significant and un-budgetable costs of downtime versus the budgetable cost of predictive monitoring.

  3. Ensure that all monitors are accessible from anywhere at any time, because whoever is assigned as the designated expert is going to need universal and uninterrupted access to the collected data or processed information.

  4. Battery monitoring is a 7x24x365 proposition. Ensure that when you commit to this capability, that you have a solid program to rely on internal and/or outsourced experts.

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