Battery voltage increases when voltmeter connected

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Discussion Overview

The discussion revolves around the phenomenon of a rechargeable AA battery's voltage appearing to increase when connected to a voltmeter. Participants explore potential explanations for this observation, including issues related to measurement techniques and external influences.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant notes that the voltage of a AA rechargeable battery increases slowly when connected to a voltmeter, expressing confusion about the cause.
  • Another participant questions the specifics of the voltage increase, asking for clarification on the initial and final voltage values and the connection methods used.
  • A different participant shares a personal experience where a similar issue occurred with a car battery, attributing the voltage increase to a dying voltmeter battery, which was resolved by replacing the voltmeter's battery.
  • Another hypothesis suggests that heat from a person's hand could enhance the chemical reactions within the battery, potentially leading to a voltage increase.
  • Several participants express curiosity about the connection methods, indicating a shared uncertainty about the proper way to connect a digital voltmeter (DVM) to a battery.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the cause of the voltage increase, with multiple competing explanations and uncertainties remaining in the discussion.

Contextual Notes

Some assumptions about the voltmeter's condition and the battery's state are not explicitly stated, and the discussion does not resolve the underlying reasons for the observed voltage behavior.

damosuz
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When I connect a AA rechargeable battery directly to a voltmeter, voltage increases slowly, regardless of the way I connect it. I can't figure out why.
 
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damosuz said:
When I connect a AA rechargeable battery directly to a voltmeter, voltage increases slowly, regardless of the way I connect it. I can't figure out why.
Increases from what to what? And what do you mean by "regardless of the way I connect it"? There aren't that many ways to connect a DVM to a battery... :smile:
 
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damosuz said:
When I connect a AA rechargeable battery directly to a voltmeter, voltage increases slowly, regardless of the way I connect it. I can't figure out why.
This happened to me last year when I was measuring the voltage on a car battery.
It turned out the battery in my voltmeter was going dead.
Replacing the battery in the voltmeter made the problem go away.
 
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Sometimes the heat from your hand is enough to boost the chemical reaction in the battery increasing the voltage.
 
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berkeman said:
Increases from what to what? And what do you mean by "regardless of the way I connect it"? There aren't that many ways to connect a DVM to a battery... :smile:
Correctly anyway. I wondered the same thing.
 

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