A device manufacturer must over-size a battery to allow for capacity to fade. Systems work well when new but concerns arise as battery capacity decreases, a loss that often happens in an uncontrolled way.
Chargers are available that offer Minimum Operational Reserve Energy (MORE) to track capacity fade. This permits the full use of each battery and prompts replacement while packs are still functional. MORE tracks Leftover Charge that should be between 10% and 20% at the end of a regular shift. Setting up MORE, the Supervisor chooses the Leftover Charge to optimize system reliability while striving for long battery life. An analogy for Leftover Charge is checking the fuel reserve when landing an aircraft. Leftover Charge is set by the Target Selector in the charger. If low at the end of a day, the target should be set higher to increase the energy backup, but if plenty of charge is left before charge, the setting can be relaxed to keep batteries longer. Figure 1 exhibits a MORE setting of 80% on a partially faded battery that keeps some spare. |
 |
Simple OperationThe charger in question works in standalone; MORE is available by connecting the charger to a PC to reveal performance data from smart batteries. This enables the supervisor to make changes on Leftover Charge with the Target Selector. Connecting to Analytics as illustrated in Figure 2 checks battery longevity relating to usage and environmental stress on data being stored. |
 |
In standalone mode, the green SoH Light on the Universal Supervisor Charger (USC) by Cadex illuminates when FCC meets the Target Selector on insertion. FCC (Full Charge Capacity) represents the digital capacity of a smart battery, a battery performance check that is made available to the user. Amber calls for service in the form of calibration that the user can do in-unit when time permits. If calibration fails to reach target capacity, the battery should be retired. |
 |
Connecting the USC to a host displays battery state-of-function by the Fishbowl as shown in Figure 4. The outer ring shows state-of-charge that moves clock-wise on charge and counter-clockwise on discharge. The Status Dome reveals the battery state, and the hanging black ceiling tracks capacity fade that slowly drops towards the redline of the Target Selector with use. Touching the Dome shows the detailed data of a smart battery. Of importance is Leftover Charge that verifies battery performance for each unique application. |
 |
The ultimate goal in risk management is predicting the Remaining Useful Life (RUL) of a battery. This level of diagnostics involves assessing the usable battery energy, observing capacity fade and securing minimum energy that MORE provides with minimal user interaction using Cloud Analytics.
Cloud AnalyticsCloud Analytics provides transparency by revealing Leftover Charge and the Energy used that is set against the Target Capacity to show RUL in years. This visualization illustrated in Figure 5 is made possible by connecting the USC to the CadexCloud. Line Products that Cloud Analytics supports also include next-gen battery analyzers and compatible rapid testers that can be configured in a vertical or horizontal system. |
 |
 |
The Vertical System shown in Figure 6 interfaces to the cloud by Ethernet or Wi-Fi to form a professional battery charging and servicing system that can be expanded to 120 channels. Each unit can run on its own program with central control from the host. The Horizontal System shown in Figure 7 serves local uses to operate in Level 2 with option to connect to the cloud with Level 3. If communication is by USB, this system is limited to the number of ports on a given host. Level 2 in the horizontal system is free of charge; Level 3 is by subscription. Cost-sensitive chargers with USB ports alone are reserved with the Horizontal System. |
Conclusion
The lone charger perceived as a necessary evil is taking on a supervisory role. MORE running in the background will serve healthcare, defense, public safety, warehousing, transportation and mining with minimal user intervention. Other applications benefiting from MORE are power tools, robots, drones and equipment rentals to prevent unexpected down-time. UN and EU regulators also realize the importance of knowing the usable battery energy and are working on battery state-of-health standards.
Batteries share similarities with machinery, a service controlled by Reliability-Centered Maintenance (RCM). Early RCM applications were the Boeing 747 implemented in the late 1960’s, a simplification in maintenance that expanded to defense, nuclear power plants, oil & gas, subways and hospitals. To avoid innovative blind spots in the haste to electrify, batteries also need an RCM type care from workforce to retirement to secure reliability and safety.
Last Updated: 12-Jan-2024
Batteries In A Portable World