Ultralife Corporation has launched the latest generation of its downhole battery monitoring system, Criterion 5, building on technology that helped one measurement-while-drilling (MWD) operator save $1.9 million annually by improving battery utilisation
The new system features real-time inclination reporting and enhanced 180°C operating capability, providing improved visibility into battery performance in demanding downhole environments.
Designed for MWD and logging-while-drilling (LWD) applications, Criterion 5 integrates embedded battery gauges with advanced management software to provide real-time battery and downhole environment insights. A compact gauge is embedded in a Lithium Thionyl Chloride (LiSOCl₂) battery pack throughout its operational life, recording and transmitting data.
Downhole tools that reach 40,000 feet expose gauges to extreme temperatures. To improve reliability, Ultralife redesigned the printed circuit board substrate, enabling operation up to 180°C while achieving a near-zero field failure rate.
Bob Fay, regional manager at Ultralife’s Houston facility, said, “A major advancement in Criterion 5 is the introduction of live inclination reporting, accurate to within 1 degree. By correlating tool orientation with battery performance metrics such as current draw and capacity consumption, operators can better understand how changing downhole conditions influence energy use. This enables faster identification of inefficiencies and more informed operational decisions.”
Additionally, the gauge monitors key parameters including shock, vibration, rotation, temperature, and current, which can be viewed through the battery management software (BMS). New extrema-tracking functionality lets users review peak values without downloading and analysing the full dataset, speeding diagnostics and event assessment.
Criterion 5 communicates monitoring data through its BMS and to downhole tool control systems via real-time CAN bus messaging. The system generates automatic warning flags when operating limits are exceeded, enabling faster responses to potentially damaging conditions. Support for CANopen and Basic CAN protocols provides flexibility for different system architectures.
To enhance data efficiency, variable-rate logging automatically increases sampling frequency during significant events and reduces it during routine operation. This ensures critical changes are captured without creating unnecessary data volumes or consuming excessive memory. Job tagging also enables users to isolate data from specific runs, simplifying analysis and supporting mission-based performance tracking.
Fay said, “Before the introduction of Criterion battery gauges and software in 2012, operators had limited visibility into downhole battery performance and often removed batteries early with substantial usable capacity remaining. For one MWD operator, that represented $1.9 million per year in avoidable costs. Criterion changed that by providing accurate insight into battery usage. With Criterion 5, operators can now understand not only how batteries are performing, but why performance changes under real downhole conditions.”
Operators can access the software via the Criterion 5 platform or the new EFR100 Compact Field Reader, a standalone battery-powered handheld device that connects to the battery pack at surface level. The EFR100 provides rapid access to battery performance and diagnostic data in locations where traditional computer-based analysis would be impractical, such as on the rig floor, at a dock, or in a warehouse, enabling faster decision-making and reduced downtime.
Combined with its new real-time inclination monitoring and high-temperature capability, Criterion 5 provides a platform to help improve downhole performance and lower operating costs.
