Description
The Keysight Self-Discharge Measurement System delivers a revolutionary reduction in the time required to measure cell self-discharge current. For smaller cells like cylindrical 18650 or 21700 cells, testing indicates that you can quickly measure stable self-discharge current in as little as 30 minutes to 2 hours, depending on the cell characteristics. And for larger capacity pouch cells (e.g., 10-60 Ah), this takes as little as1-4 hours. That‘s a significant improvement compared to waiting weeks or months for the cell OCV to change enough to determine cell quality. And it significantly decreases your test cycle and improves your time to market. The Self-Discharge Measurement System quickly measures self-discharge current using a potentiostatic measurement method with the characteristics needed to accurately make the direct current measurement: Minimum disturbance of the cell The voltage applied to the cell is quickly matched (± 5 μV) to the actual cell voltage. This minimizes any new charge or discharge and thus limits any new RC settling to a minimum. The voltage applied to the cell is very stable (± 10 μVpk) to minimize continuing charge redistribution current noise on the self-discharge current measurement. Accurately measures low-level self-discharge currents to ±(0.025% + 100nA) The Self-Discharge Measurement System also measures the cell temperature. This allows you to see how cell V and self-discharge current vary with temperature. Since cells have a complex temperature coefficient for their voltage, monitoring cell temperature allows you to control or eliminate changes in cell voltage caused by changes in temperature. And controlling those voltage changes eliminates a significant source of error in the self-discharge current measurement. You can use the T-type thermocouple supplied with the BT2191A or provide your own sensor and wiring. Supported sensors include T, J, K, E, N, R-type thermocouples; 5kΩ thermistor; Pt100 & Pt1000 RTDs.
