Battery Cyclers

A battery cycler will analyse battery function through charge/discharge cycles, by measuring the cells response over time. During battery cycling, a number of parameters can be measured, including capacity,  efficiency of the battery and self-discharge. The battery cycler is also suitable for use with capacitors and supercapacitors.

Each module of the BCS-9xx series is composed of 8 channels, and is equipped with five charge currents ranges. The BT-Lab software offers great usability for battery cycling. With the Modulobat technique it is possible to work with 11 different control modes, which allows for easy programming of unique sequences.

In battery cycling, the classic charge/discharge testing measures the net result of all the electrochemical processes taking place inside the cell. In addition to charge/discharge testing, the use of Electrochemical Impedance Spectroscopy (one of the control modes) has become more popular in recent years. EIS, especially in the low frequency range, can be used to monitor and control the degradation of the battery,

What processes are generally involved in battery cycling/testing?

1. Initial Conditioning (optional): Some tests include a preliminary conditioning phase to stabilize the battery.
2. Charging: The battery is charged at a specified current or voltage until it reaches the target state of charge.
3. Rest Periods: The battery may be idle for a set time to allow temperature and voltage stabilization.
4. Discharging: The battery is discharged at a controlled current or voltage to assess capacity and performance.
5. Data Recording: Voltage, current, capacity, and other parameters are measured and logged during each cycle.
6. Repeat Cycles: The charge-discharge cycle is repeated multiple times to evaluate cycling stability, capacity fade, and overall lifespan.
7. Electrochemical Impedance Spectroscopy (EIS)(optional):  By applying small alternating current signals and measuring the response across different frequencies, EIS helps to provide detailed information on internal battery processes, such as charge transfer resistance and diffusion.
8. Final Analysis: After completing the desired number of cycles, data are analyzed to determine capacity degradation, efficiency, internal resistance, and other key metrics.

This process helps evaluate battery durability, efficiency, and suitability for specific applications.

The state-of-the-art-system is modular, and has superior performance and specifications. These include the 5 current ranges (every decade), 18 bit resolution in current and voltage, high precision coulometry, fast bandwidths (rise and fall times), smart sampling, interfacing with external equipment and temperature probes and many more.

Another unique feature of the BCS-9xx battery cyclers is the capability of doing Electrochemical Impedance Spectroscopy (EIS) experiments. With a frequency range of 10 kHz to 10 mHz the BCS-9xx battery cycler is Ideal for studying battery properties.

A method to determine the lifespan of batteries in a relatively short period (weeks) without the need to operate at elevated temperatures is High precision Coulometry (HPC). High precision coulometry was developed in 2010 by Dr. Jeff Dahn’s laboratory at Dalhousie University, Nova Scotia, Canada and requires very accurate measurements of the charge/discharge quantities from a battery. Degradation rates are calculated from the difference between charge and discharge values. The BCS-9xx battery cyclers deliver ultra-high precision measurements for optimal predictions.

A battery cycler measures the performance and characteristics of a battery by cycling it through charge and discharge processes. Specifically, it records data such as:

• Capacity: The amount of charge the battery can store and deliver, typically in milliamp-hours (mAh) or amp-hours (Ah).
• Voltage: The voltage output during charging and discharging cycles.
• Current: The flow of charge during the cycling process.
• Charge/Discharge Efficiency: The efficiency of the battery in storing and releasing energy.
• Cycle Life: The number of charge/discharge cycles the battery can undergo before its capacity significantly degrades.
• Resistance: Internal resistance that can affect performance.
• State of Charge (SoC) and State of Health (SoH): Indicators of current performance and overall health of the battery.

Battery cyclers are used in testing, research, and quality control to evaluate battery performance, durability, and stability over multiple cycles.

Simulation of complex battery cycles that model real life activity.

The BT-Lab software allows you to simulate real-life activity, like the profile for an electric car driving in an urban area during rush hour. Such a simulation requires thousands of steps, which makes the creation of such files very difficult and time consuming. To make this easier, there is a tool in the software to import a txt file to mimic this kind of profile. Furthermore, algorithms will check a number of parameters or mismatch with the instrument or the battery, and warn the user during programming of a test cycle.

Supercapacitors

Supercapacitors are among the most promising devices for energy storage. These capacitors deliver charge much faster than batteries, and tolerates many more charge and discharge cycles than rechargeable batteries. Using a battery cycler, the charge/discharge capacities can be investigated with a potential scan and constant power discharge.

These potentiodynamic and constant power discharges allow you to characterize the cycling performance of the supercapacitor. Using these characterizations, it is possible to determine if the studied supercapacitor fits the need (according to its corresponding pulse output) of the electronic device to powered.