The Rise and Fall of PowerCheck

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Duracell PowerCheck: A genius idea which didn't last that long

Technology Connections

Oct 8, 2024

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Science & Technology

Duracell PowerCheck simplified battery testing

  1. The phrase 'batteries not included' was common before 2010, as many gadgets relied on AA or AAA batteries. The choice between these sizes often seemed arbitrary, with AA batteries offering longer life but sometimes being replaced by AAA in designs.
  2. Duracell PowerCheck was a feature introduced in the late '90s, allowing users to test a battery's charge without a separate tester. This innovation was also adopted by some competitors.
  3. The concept of integrating a battery tester into the battery itself originated from Kodak, leading to patent disputes with James R. Burroughs, who had a similar idea. Both patents were approved, causing some legal issues.
  4. The Duracell PowerCheck worked by measuring the battery's voltage, which drops as the battery discharges. Fresh batteries have a voltage of around 1.5 to 1.6 volts, which decreases as they are used.
  5. A multimeter can be used to check a battery's voltage, with a reading of 1.57 volts indicating a new or barely used battery, while 1.06 volts suggests the battery is nearly dead.

Duracell's built-in battery tester was innovative

  1. The text discusses a method to test batteries without a load, which is not perfect but fairly reliable. It requires a multimeter and knowledge of acceptable voltage drop.
  2. Inexpensive battery testers are essentially analog voltmeters with a scale indicating good or bad battery status.
  3. Duracell innovated by integrating a voltmeter into the battery itself, allowing users to test the battery by pressing dots on it.
  4. The battery's testing mechanism is temperature-dependent, requiring testing at 70 degrees Fahrenheit or 21 degrees Celsius.
  5. To test the battery, users had to press the dots hard, causing a bar to turn yellow, indicating the battery's charge level.
  6. The yellow bar is activated by heat, using thermochromic material that changes color with temperature, similar to mood rings or aquarium thermometers.
  7. The testing mechanism is built into the battery's label, with one testing dot on the negative terminal and the other on the battery's shell.

Duracell PowerCheck's innovative battery tester

  1. The Duracell PowerCheck feature allows users to test a battery's charge by pressing dots on the battery label, which completes a circuit to a tiny heater.
  2. The testing mechanism involves conductive pads on the battery's label, with a metal foil contact patch on the positive side and less visible grey patches on the negative side.
  3. An insulating layer prevents the contact patch from touching the battery shell unless pressed, completing a circuit that activates a heater connected to thermochromic material.
  4. The heater's design includes a varying cross-sectional area, creating a gradient of heat output, which allows users to gauge the battery's remaining charge beyond a simple pass/fail.
  5. The heater's resistance varies along its length, causing different voltage drops and heating levels, which indicate the battery's strength by how much of the indicator turns yellow.
  6. A demonstration with a DC power supply shows that at lower voltages, only part of the indicator turns yellow, illustrating the battery's diminishing charge.

Duracell PowerCheck's brief utility

  1. The Duracell PowerCheck used a simple yet effective technology to measure battery life by heating a thermochromic indicator. This method provided a visual representation of the battery's remaining life by changing color based on the heat generated by the battery's voltage.
  2. The design included a beige insulator that served dual purposes: it electrically insulated the components and thermally isolated the indicator from the battery shell. This was crucial because the battery shell's thermal conductivity could otherwise dissipate the heat needed to change the indicator's color.
  3. Testing the battery consumed a small amount of its capacity, as the battery powered the heater used in the test. This consumption, however, allowed for a more accurate reading under load conditions, which is essential for assessing the battery's true capacity.
  4. Despite the innovative design, the PowerCheck feature was short-lived due to patent disputes and the realization that most consumers did not regularly test their batteries. The feature was useful but not widely utilized, leading to its discontinuation.
  5. The text highlights a comparison between the PowerCheck's accuracy and a multimeter's reading. While the multimeter might show a decent voltage, the PowerCheck could reveal the battery's inability to sustain current, thus providing a more practical assessment of its usability.

Duracell's battery tester was underutilized

  1. Most people use batteries until they are fully depleted and then replace them, rather than storing partially-used batteries for later use. This common usage pattern questions the necessity of having a battery tester on each battery.
  2. Batteries are generally commodity items, and consumers often choose them based on cost rather than features like built-in testers, which can make them more expensive and less appealing.
  3. The built-in battery testers, like Duracell's PowerCheck, were seen as a gimmick by some users, as they were difficult to use and added unnecessary cost.
  4. For those who do keep partially-used batteries, a separate battery tester or simply testing them in a device could be more practical than having a tester on each battery.
  5. Duracell's inclusion of battery testers was a response to a perceived frustration that was not as widespread as assumed, leading to the feature being underutilized.
  6. The shift towards rechargeable batteries has reduced the demand for disposable batteries, making features like built-in testers even less relevant.

Duracell PowerCheck's limited impact

  1. The text reflects on the frequent use of AA batteries in devices like Game Boys, Walkmans, and cameras, highlighting the past necessity of constant battery replacement. It notes that modern devices often indicate battery charge levels, reducing the need for external testers.
  2. The author expresses gratitude to Luis Solano for suggesting the video topic and to Ernie Smith for providing a comprehensive Tedium article that aided in research. The video was initially planned for November but was moved up due to production issues.
  3. The text humorously mentions the challenges faced during the video production, including difficulties with delivery and script errors, adding a light-hearted tone to the narrative.
  4. It discusses the history of battery testers, particularly the Duracell PowerCheck, which allowed users to check battery charge by pressing dots. The author notes the frustration with using these testers and their limited production in certain markets.
  5. The author shares a personal anecdote about being a value-conscious consumer, preferring generic brands or discounted Rayovac batteries, and questions whether this narrative serves as an end-captions gag.