AMR units still going strong after 25 years on their original batteries


Buedingen, Germany — (METERING.COM) — February 10, 2010 – Twenty-five years ago, Aclara™ (formerly Hexagram, Inc.) began installing hundreds of thousands of battery-powered automatic meter reading (AMR) devices for the utility market and virtually all of these devices are still operating on their original battery – a single Tadiran TL-2100 AA-size lithium thionyl chloride battery – with laboratory confirming that they had retained nearly 25 percent of their original capacity.

Subsequently the company has introduced a newer generation of STAR® Network wireless fixed network AMR systems using an upgraded Tadiran TL-4903 “XOL” (eXtended Operating Life) AA-size lithium thionyl battery, which features 33 percent higher capacity (2.4Ah vs. 1.8 Ah) and lower self discharge than the TL-2100 battery. The TL-4903 (equivalent to SL-860) battery was selected based on its performance characteristics, including higher energy density, higher capacity, a temperature range of 55ºC to +125ºC, and 20+ year service life.

STAR network meter transmitter units (MTUs) are capable of providing multiple daily readings using narrow-band radio frequency to communicate with data collection units (DCUs) strategically positioned on buildings or utility poles located approximately 1 to 2 miles apart. These units combine intelligent energy saving design with advanced lithium thionyl chloride battery chemistry to deliver proven 20-year service life. To conserve energy, data transmission is initiated by a timer at programmed intervals. Use of one-way transmission also results in a less complex, lower cost system.

The life cycle savings that can be achieved with a 20+ year AMR unit are substantial compared to a unit with an expected service life of 7 to 10 years, as cost savings begin to accrue in year 7 and continue throughout the 20-year product life cycle. For example, a utility with 5,000 service connections could realize up to $200,000 in total cost savings over a ten year period by eliminating all battery changeouts during that 10-year period, assuming that the cost of each battery changeout is approximately $40 per site. If a second round of battery changeouts were eliminated over a 20-year period, the potential $400,000 in savings could be achieved for every 5,000 service connections. These savings would be above and beyond the labor savings associated with eliminating visual meter reading.