Thevenin equivalent circuit components of the silver oxide-zinc battery in energy generation and absorption phases
Keywords:battery circuit components, silver oxide-zinc battery
The paper concerns the determination of the Thevenin equivalent circuit components of the 1.55V, 24mAh Ag2O-Zn button battery using a transient circuit analysis method. This battery is used to power small profile packaged microcircuits in medical devices and wearable bioelectronics. For a typical battery at full charge, the series resistance, contact resistance and double layer capacitance are respectively, 28.6Ω, 10.5Ω and 0.06F in the power absorbing phase, and 35Ω, 10.5Ω and 0.08F in the power generating phase. For a given battery, the internal series resistance in the generating phase is greater than the corresponding resistance in the absorbing one. This applies to batteries at both 100% and 70% state of charge (SOC). At 70% SOC the series resistances in both absorbing and generating phases fall to about half of their respective values at 100% SOC. The power dissipated in the battery during generation is greater than during absorption. The electrode double layer capacitance is in the 0.06F to 0.1F range. Transient time constants vary from 0.3 to 0.9 seconds. The resulting equivalent model is useful in the analysis of battery operated microcircuits in providing insight into their dc and transient responses.
Copyright (c) 2022 Karl Norian
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