Charge cycle

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A charge cycle is the process of charging a rechargeable battery and discharging it as required into a load. The term is typically used to specify a battery's expected life, as the number of charge cycles affects life more than the mere passage of time. Discharging the battery fully before recharging may be called "deep discharge"; partially discharging then recharging may be called "shallow discharge".

A "charge cycle" is not a unit of time; the length of time spent charging or discharging does not affect the number of charge cycles. [1] Each battery is affected differently by charge cycles. [2] [3]

In general, number of cycles for a rechargeable battery (the cycle life) indicates how many times it can undergo the process of complete charging and discharging until failure or starting to lose capacity. [4] [5] [6] [7]

Apple Inc. clarifies that a charge cycle means using all the battery's capacity, but not necessarily by discharging it from 100% to 0%: "You complete one charge cycle when you’ve used (discharged) an amount that equals 100% of your battery’s capacity — but not necessarily all from one charge. For instance, you might use 75% of your battery’s capacity one day, then recharge it fully overnight. If you use 25% the next day, you will have discharged a total of 100%, and the two days will add up to one charge cycle." [8]

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<span class="mw-page-title-main">Nickel–cadmium battery</span> Type of rechargeable battery

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<span class="mw-page-title-main">Lithium-ion battery</span> Rechargeable battery type

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<span class="mw-page-title-main">Rechargeable battery</span> Type of electrical battery

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<span class="mw-page-title-main">AA battery</span> Standardized type of battery

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<span class="mw-page-title-main">Battery charger</span> Device used to provide electricity

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<span class="mw-page-title-main">Deep-cycle battery</span> Electrical storage system built for intensive discharging

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Depth of discharge (DoD) is an important parameter appearing in the context of rechargeable battery operation. Two non-identical definitions can be found in commercial and scientific sources. The depth of discharge is defined as:

  1. the maximum fraction or percentage of a battery's capacity which is removed from the charged battery on a regular basis. "Charged" does not necessarily refer to fully or 100 % charged, but rather to the state of charge (SoC), where the battery charger stops charging, which is achieved by different techniques.
  2. the fraction or percentage of the battery's capacity which is currently removed from the battery with regard to its (fully) charged state. For fully charged batteries, the depth of discharge is connected to the state of charge by the simple formula . The depth of discharge then is the complement of state of charge: as one increases, the other decreases. This definition is mostly found in scientific sources.
<span class="mw-page-title-main">Lithium–sulfur battery</span> Type of rechargeable battery

The lithium–sulfur battery is a type of rechargeable battery. It is notable for its high specific energy. The low atomic weight of lithium and moderate atomic weight of sulfur means that Li–S batteries are relatively light. They were used on the longest and highest-altitude unmanned solar-powered aeroplane flight by Zephyr 6 in August 2008.

<span class="mw-page-title-main">Electric battery</span> Power source with electrochemical cells

A battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negative terminal is the anode. The terminal marked negative is the source of electrons that will flow through an external electric circuit to the positive terminal. When a battery is connected to an external electric load, a redox reaction converts high-energy reactants to lower-energy products, and the free-energy difference is delivered to the external circuit as electrical energy. Historically the term "battery" specifically referred to a device composed of multiple cells; however, the usage has evolved to include devices composed of a single cell.

The lithium–air battery (Li–air) is a metal–air electrochemical cell or battery chemistry that uses oxidation of lithium at the anode and reduction of oxygen at the cathode to induce a current flow.

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This is a list of commercially-available battery types summarizing some of their characteristics for ready comparison.

Capacity loss or capacity fading is a phenomenon observed in rechargeable battery usage where the amount of charge a battery can deliver at the rated voltage decreases with use.

Research in lithium-ion batteries has produced many proposed refinements of lithium-ion batteries. Areas of research interest have focused on improving energy density, safety, rate capability, cycle durability, flexibility, and cost.

References

  1. Preger, Yuliya; Barkholtz, Heather M.; Fresquez, Armando; Campbell, Daniel L.; Juba, Benjamin W.; Romàn-Kustas, Jessica; Ferreira, Summer R.; Chalamala, Babu (1 August 2022). "Degradation of Commercial Lithium-Ion Cells as a Function of Chemistry and Cycling Conditions". Journal of the Electrochemical Society. 167 (12): 120532. doi: 10.1149/1945-7111/abae37 . S2CID   225506214.
  2. "Understanding the Trilemma of Fast Charging, Energy Density and Cycle Life of Lithium-ion Batteries". 1 August 2022.
  3. "Powerstation im Test" (in German). 1 August 2022.
  4. Tony Bove (2 February 2010). iPod & iTunes For Dummies, Book + DVD Bundle. John Wiley & Sons. p. 26. ISBN   978-0-470-59070-6 . Retrieved 19 June 2013.
  5. G. S. George (1 January 2007). Applied Science II. Technical Publications. p. 8. ISBN   978-81-8431-146-4.
  6. United Nations (2009). Recommendations on the Transport of Dangerous Goods: Manual of Tests and Criteria. United Nations Publications. p. 394. ISBN   978-92-1-139135-0.
  7. Davide Andrea (2010). Battery Management Systems for Large Lithium Ion Battery Packs. Artech House. p. 189. ISBN   978-1-60807-105-0 . Retrieved 19 June 2013.
  8. Batteries - Why Lithium-ion? - Apple