Editing Smartphone (section)

===Battery===
Smartphones typically feature [[lithium-ion battery|lithium-ion]] or [[lithium-polymer battery|lithium-polymer batteries]] due to their high [[energy density|energy densities]].

Batteries chemically wear down as a result of repeated charging and discharging throughout ordinary usage, losing both energy capacity and output power, which results in loss of processing speeds followed by system outages.<ref>{{cite web |title=Causes and Fixes of Unexpected Phone Shutoffs - RTCL ... rtcl.eecs.umich.edu › assets › 2020 |url=https://rtcl.eecs.umich.edu/rtclweb/assets/publications/2020/youngmoon-mobisys20.pdf |date=2020-06-15}}</ref> Battery capacity may be reduced to 80% after few hundred recharges, and the drop in performance accelerates with time.<ref>{{cite web |last1=Jasieniak |first1=Jacek |title=Explainer: how to extend your phone's battery life |url=https://theconversation.com/explainer-how-to-extend-your-phones-battery-life-80958 |website=The Conversation |date=July 31, 2017 |language=en}}</ref><ref>{{cite journal |url=https://www.ukm.my/jqma/v10_1/jqma-10-1-paper4.pdf |title=Modelling of Charge/Discharge Cycle of Lithium Ion Battery System |first1=Ho Kar |last1=Yee |first2=Sivakumar |last2=Ramakrishnan |first3=Ahmad Azmin |last3=Mohamad |journal=Journal of Quality Measurement and Analysis |volume=10 |issue=1 |date=2014 |pages=39–47}}</ref>
Some mobile phones are designed with batteries that can be interchanged upon expiration by the end user, usually by opening the back cover. While such a design had initially been used in most mobile phones, including those with touch screen that were not Apple iPhones, it has largely been usurped throughout the 2010s by permanently built-in, non-replaceable batteries; a design practice criticized for [[Planned obsolescence#Batteries|planned obsolescence]].<ref>{{cite web |title=Planned obsolescence: the outrage of our electronic waste mountain |url=https://www.theguardian.com/technology/2020/apr/15/the-right-to-repair-planned-obsolescence-electronic-waste-mountain |website=the Guardian |language=en |date=15 April 2020}}</ref>

====Charging====
[[File:USB battery charger.jpg|thumb|A high-capacity portable [[battery charger]] ([[Battery charger#Power bank|''power bank'']])]]

Due to limitations of [[electrical current]]s that existing USB cables' copper wires could handle, charging protocols which make use of elevated [[voltages]] such as [[Qualcomm Quick Charge]] and [[MediaTek Pump Express]] have been developed to increase the power throughput for faster charging, to maximize the usage time without restricted ergonomy and to minimize the time a device needs to be attached to a power source.

The smartphone's integrated [[charge controller]] (IC) requests the elevated voltage from a supported [[mobile phone charger|charger]]. "[[VOOC]]" by Oppo, also marketed as "dash charge", took the counter approach and increased current to cut out some heat produced from internally regulating the arriving voltage in the end device down to the battery's charging terminal voltage, but is incompatible with existing USB cables, as it requires the thicker copper wires of high-current USB cables. Later, [[USB Power Delivery]] (''USB-PD'') was developed with the aim to standardize the negotiation of charging parameters across devices of up to 100 Watts, but is only supported on cables with USB-C on both endings due to the connector's dedicated PD channels.<ref>{{cite web |last1=Rao |first1=Sumukh |title=Qualcomm Quick Charge vs OnePlus Warp Charge vs Oppo VOOC vs USB-PD - TechPP |url=https://techpp.com/2020/04/09/qualcomm-quick-charge-vs-oneplus-warp-charge-vs-oppo-vooc-vs-usb-pd/ |website=techpp.com |access-date=9 December 2021 |date=2020-04-09}}</ref>

While charging rates have been increasing, with 15 [[watt]]s in 2014,<ref>{{cite web |last1=Ho |first1=Joshua |title=The Samsung Galaxy Note 4 Review |url=https://www.anandtech.com/show/8613/the-samsung-galaxy-note-4-review/3 |website=www.anandtech.com |date=2014}}</ref> 20 Watts in 2016,<ref>{{cite web |last1=T |first1=Nick |title=How it works: Dash Charge fast charging on the OnePlus 3 |url=https://www.phonearena.com/news/How-it-works-Dash-Charge-fast-charging-on-the-OnePlus-3_id82646 |website=Phone Arena |date=2016-06-30}}</ref> and 45 watts in 2018,<ref>{{cite web |last1=Byford |first1=Sam |title=Oppo has the fastest fast charging we've ever seen |url=https://www.theverge.com/circuitbreaker/2018/10/10/17958648/oppo-super-vooc-fast-charging-find-x-lamborghini-edition |website=The Verge |language=en |date=10 October 2018}}</ref> the power throughput may be throttled down significantly during operation of the device.<ref>{{cite web |title=PSA: The Galaxy S8 and S8+ doesn't actually Fast Charge while you're using it – Phandroid |url=https://phandroid.com/2017/05/11/samsung-galaxy-s8-plus-wont-fast-charge-problems/ |website=phandroid.com |date=11 May 2017}}</ref>{{efn|I.e. while the device is not in stand-by mode or charging while the main operating system is powered off.}}

[[Wireless charging]] has been widely adapted, allowing for intermittent recharging without wearing down the charging port through frequent reconnection, with [[Qi (standard)|''Qi'']] being the most common standard, followed by [[Powermat]]. Due to the lower efficiency of wireless power transmission, charging rates are below that of wired charging, and more heat is produced at similar charging rates.

By the end of 2017, smartphone battery life has become generally adequate;<ref>{{cite web|title=6 phones with the best battery life|url=https://www.cnet.com/news/smartphones-best-long-battery-life/|access-date=October 31, 2017}}</ref> however, earlier smartphone battery life was poor due to the weak batteries that could not handle the significant power requirements of the smartphones' computer systems and color screens.<ref>{{cite press release|title=J.D. Power and Associates Reports: Smartphone Battery Life has Become a Significant Drain on Customer Satisfaction and Loyalty|url=http://www.prnewswire.com/news-releases/jd-power-and-associates-reports-smartphone-battery-life-has-become-a-significant-drain-on-customer-satisfaction-and-loyalty-142765065.html|access-date=September 11, 2014}}</ref><ref>{{cite web |first=James |last=Kendrick |url=https://www.zdnet.com/article/the-secret-behind-poor-smartphone-battery-life/ |title=The secret behind poor smartphone battery life|work=ZDNet |date=August 4, 2014 |access-date=November 2, 2017}}</ref><ref>{{cite magazine|url=https://techland.time.com/2013/04/01/peak-battery-why-smartphone-battery-life-still-stinks-and-will-for-years/ |title=Peak Battery: Why Smartphone Battery Life Still Stinks, and Will for Years|magazine=[[Time (magazine)|Time]] | date=April 1, 2013}}</ref>

Smartphone users purchase additional chargers for use outside the home, at work, and in cars and by buying portable external "battery packs". External battery packs include generic models which are connected to the smartphone with a cable, and custom-made models that "piggyback" onto a smartphone's case. In 2016, Samsung had to recall millions of the [[Galaxy Note 7]] smartphones due to an explosive battery issue.<ref>{{cite web|url=http://www.digitaltrends.com/mobile/samsung-halts-galaxy-note-7-shipments-phones-catching-fire/|title=Refurbished version of ill-fated Galaxy Note 7 will soon be available overseas|date=May 5, 2017}}</ref> For consumer convenience, [[inductive charging|wireless charging]] stations have been introduced in some hotels, bars, and other public spaces.<ref>{{Cite magazine|url=https://www.wired.com/story/iphone-wireless-charging-qi/|title=The Most Impactful New iPhone Feature May Be the Most Boring|magazine=WIRED|access-date=2017-09-22|language=en-US}}</ref>

====Power management====
A technique to minimize power consumption is the panel self-refresh, whereby the image to be shown on the display is not sent at all times from the processor to the integrated controller (IC) of the display component, but only if the information on screen is changed. The display's integrated controller instead memorizes the last screen contents and refreshes the screen by itself. This technology was introduced around 2014 and has reduced power consumption by a few hundred milliwatts.<ref>{{cite web |last1=Frumusanu |first1=Andrei |title=Analysing AMOLED Power Efficiency Improvements |url=https://www.anandtech.com/show/9394/analysing-amoled-power-efficiency |website=www.anandtech.com |access-date=14 September 2023 |date=2015-06-23}}</ref>