Phase Meter Measurement of State of Charge for Satellite NiCd Cells: A Preliminary Study.
Abstract
Experiments were performed to determine if the phase angle between alternating voltage and current could be used to predict, within a probable error of 5%, the state of charge of seven individual sealed (General Electric) model 10AB08 NiCd) cells and a battery consisting of the seven cells in series. The cells were charged for various lengths of time at 0.8 A to obtain a range of state of charge; their phase angles were measured with a Hewlett-Packard HP3575A gain-phase meter at 35 Hz; and they were discharged at 5 A 0.1 V to determine their state of charge in ampere-hours of capacity. The phase angle state-of-charge data were subjected to second-order polynomial curve fitting by means of least-squares analysis. The probable errors obtained from the least-squares analysis were used to judge the quality of the measured correlation between phase angle and state of charge. In order to determine how the correlation might be affected through cell use, the four extensively cycled cells with more than 3700 charge-discharge cycles and three cells with less than 40 such cycles were tested. The effect of temperature on the correlation was also studied.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 30, 1979
- Accession Number
- ADA084907
Entities
People
- Charles C. Badcock
- Michael R. Martinelli
- Stanley W. Mayer
Organizations
- The Aerospace Corporation