92-445: A cloudbook is a class of laptop computer , originally defined as any lightweight laptop with a small solid-state drive (SSD), built-in Wi-Fi , and a minimal operating system configured to prioritize web browsing , web applications , and cloud storage . The concept emerged in 2007 with the cancelled Palm Foleo . In 2010, Google announced a reference design for a cloudbook running
184-419: A "20-hour" rate), while typical charging and discharging may occur at C/2 (two hours for full capacity). The available capacity of electrochemical cells varies depending on the discharge rate. Some energy is lost in the internal resistance of cell components (plates, electrolyte, interconnections), and the rate of discharge is limited by the speed at which chemicals in the cell can move about. For lead-acid cells,
276-437: A battery charger using AC mains electricity , although some are equipped to use a vehicle's 12-volt DC power outlet. The voltage of the source must be higher than that of the battery to force current to flow into it, but not too much higher or the battery may be damaged. Chargers take from a few minutes to several hours to charge a battery. Slow "dumb" chargers without voltage or temperature-sensing capabilities will charge at
368-447: A hard disk drive (HDD) for storage; since then, solid-state drives (SSD) have gradually come to supplant hard drives in all but some inexpensive consumer models. Solid-state drives are faster and more power-efficient, as well as eliminating the hazard of drive and data corruption caused by a laptop's physical impacts, as they use no mechanical parts such as a rotational platter. In many cases, they are more compact as well. Initially, in
460-417: A separate graphics processor were limited in their utility for gaming and professional applications involving 3D graphics, but the capabilities of CPU-integrated graphics have converged with the low-end of dedicated graphics processors since the mid-2010s. For laptops possessing limited onboard graphics capability but sufficient I/O throughput, an external GPU (eGPU) can provide additional graphics power at
552-621: A battery rather than to operate the radio directly. Flashlights may be driven by a dynamo directly. For transportation, uninterruptible power supply systems and laboratories, flywheel energy storage systems store energy in a spinning rotor for conversion to electric power when needed; such systems may be used to provide large pulses of power that would otherwise be objectionable on a common electrical grid. Ultracapacitors – capacitors of extremely high value – are also used; an electric screwdriver which charges in 90 seconds and will drive about half as many screws as
644-399: A battery. For some types, the maximum charging rate will be limited by the speed at which active material can diffuse through a liquid electrolyte. High charging rates may produce excess gas in a battery, or may result in damaging side reactions that permanently lower the battery capacity. Very roughly, and with many exceptions and caveats, restoring a battery's full capacity in one hour or less
736-571: A battery. To avoid damage from the cell reversal effect, it is necessary to access each cell separately: each cell is individually discharged by connecting a load clip across the terminals of each cell, thereby avoiding cell reversal. If a multi-cell battery is fully discharged, it will often be damaged due to the cell reversal effect mentioned above. It is possible however to fully discharge a battery without causing cell reversal—either by discharging each cell separately, or by allowing each cell's internal leakage to dissipate its charge over time. Even if
828-414: A broad range of devices, which combined features of several previously separate device types. The hybrids , convertibles , and 2-in-1s emerged as crossover devices, which share traits of both tablets and laptops. All such devices have a touchscreen display designed to allow users to work in a tablet mode, using either multi-touch gestures or a stylus / digital pen . Convertibles are devices with
920-466: A cell is brought to a fully discharged state without reversal, however, damage may occur over time simply due to remaining in the discharged state. An example of this is the sulfation that occurs in lead-acid batteries that are left sitting on a shelf for long periods. For this reason it is often recommended to charge a battery that is intended to remain in storage, and to maintain its charge level by periodically recharging it. Since damage may also occur if
1012-443: A device using a rechargeable battery was introduced in 2007, and similar flashlights have been produced. In keeping with the concept of ultracapacitors, betavoltaic batteries may be utilized as a method of providing a trickle-charge to a secondary battery, greatly extending the life and energy capacity of the battery system being employed; this type of arrangement is often referred to as a "hybrid betavoltaic power source" by those in
SECTION 10
#17328526388661104-428: A discharged cell in this way causes undesirable and irreversible chemical reactions to occur, resulting in permanent damage to the cell. Cell reversal can occur under a number of circumstances, the two most common being: In the latter case, the problem occurs due to the different cells in a battery having slightly different capacities. When one cell reaches discharge level ahead of the rest, the remaining cells will force
1196-458: A few high-end models intended for gaming do as well. As of 2021, 8 GB RAM is most common, with lower-end models occasionally having 4 GB. Higher-end laptops may come with 16 GB of RAM or more. The earliest laptops most often used floppy disk for storage, although a few used either RAM disk or tape, by the late 1980s hard disk drives had become the standard form of storage. Between 1990 and 2009, almost all laptops typically had
1288-405: A full-featured desktop OS like Windows 10 , and have a number of typical laptop I/O ports, such as USB 3 and Mini DisplayPort . 2-in-1s are designed to be used not only as a media consumption device but also as valid desktop or laptop replacements, due to their ability to run desktop applications, such as Adobe Photoshop . It is possible to connect multiple peripheral devices, such as
1380-462: A hybrid lead–acid battery and ultracapacitor invented by Australia's national science organisation CSIRO , exhibits tens of thousands of partial state of charge cycles and has outperformed traditional lead-acid, lithium, and NiMH-based cells when compared in testing in this mode against variability management power profiles. UltraBattery has kW and MW-scale installations in place in Australia, Japan, and
1472-537: A hydrogen-absorbing alloy for the negative electrode instead of cadmium . The lithium-ion battery was introduced in the market in 1991, is the choice in most consumer electronics, having the best energy density and a very slow loss of charge when not in use. It does have drawbacks too, particularly the risk of unexpected ignition from the heat generated by the battery. Such incidents are rare and according to experts, they can be minimized "via appropriate design, installation, procedures and layers of safeguards" so
1564-592: A laptop and provide display output over one USB-C Cable. Most laptop displays have a maximum refresh rate of 60 Hz. The Dell M17x and Samsung 700G7A, both released in 2011, were among the first laptops to feature a 120 Hz refresh rate, and more such laptops have appeared in the years since. A laptop's CPU has advanced power-saving features and produces less heat than one intended purely for desktop use. Mainstream laptop CPUs made after 2018 have at least two processor cores, often four cores, and sometimes more, with 6 and 8 cores becoming more common. For
1656-871: A load, and recharged many times, as opposed to a disposable or primary battery , which is supplied fully charged and discarded after use. It is composed of one or more electrochemical cells . The term "accumulator" is used as it accumulates and stores energy through a reversible electrochemical reaction . Rechargeable batteries are produced in many different shapes and sizes, ranging from button cells to megawatt systems connected to stabilize an electrical distribution network . Several different combinations of electrode materials and electrolytes are used, including lead–acid , zinc–air , nickel–cadmium (NiCd), nickel–metal hydride (NiMH), lithium-ion (Li-ion), lithium iron phosphate (LiFePO4), and lithium-ion polymer (Li-ion polymer). Rechargeable batteries typically initially cost more than disposable batteries but have
1748-551: A long and stable lifetime. The effective number of cycles is above 5000 and the battery is not damaged by deep discharge. The energy density is rather low, somewhat lower than lead–acid. A rechargeable battery is only one of several types of rechargeable energy storage systems. Several alternatives to rechargeable batteries exist or are under development. For uses such as portable radios , rechargeable batteries may be replaced by clockwork mechanisms which are wound up by hand, driving dynamos , although this system may be used to charge
1840-473: A low rate, typically taking 14 hours or more to reach a full charge. Rapid chargers can typically charge cells in two to five hours, depending on the model, with the fastest taking as little as fifteen minutes. Fast chargers must have multiple ways of detecting when a cell reaches full charge (change in terminal voltage, temperature, etc.) to stop charging before harmful overcharging or overheating occurs. The fastest chargers often incorporate cooling fans to keep
1932-510: A mouse, keyboard, and several external displays to a modern 2-in-1. Microsoft Surface Pro-series devices and Surface Book are examples of modern 2-in-1 detachable, whereas Lenovo Yoga -series computers are a variant of 2-in-1 convertibles. While the older Surface RT and Surface 2 have the same chassis design as the Surface Pro, their use of ARM processors and Windows RT do not classify them as 2-in-1s, but as hybrid tablets. Similarly,
SECTION 20
#17328526388662024-888: A much lower total cost of ownership and environmental impact , as they can be recharged inexpensively many times before they need replacing. Some rechargeable battery types are available in the same sizes and voltages as disposable types, and can be used interchangeably with them. Billions of dollars in research are being invested around the world for improving batteries as industry focuses on building better batteries. Devices which use rechargeable batteries include automobile starters , portable consumer devices, light vehicles (such as motorized wheelchairs , golf carts , electric bicycles , and electric forklifts ), road vehicles (cars, vans, trucks, motorbikes), trains, small airplanes, tools, uninterruptible power supplies , and battery storage power stations . Emerging applications in hybrid internal combustion-battery and electric vehicles drive
2116-479: A new type of cloudbook was pushed by Microsoft starting in 2015; the first such cloudbook released was Acer 's Aspire One Cloudbook in 2015. Later cloudbooks were released by Asus and HP ( HP Stream ). Microsoft-partnered cloudbook manufacturers typically sold their machines with one-year free subscription offers for both Office 365 and OneDrive , cloud-based productivity software and file storage, respectively, from Microsoft. This computer hardware article
2208-742: A number of hybrid laptops run a mobile operating system , such as Android . These include Asus's Transformer Pad devices, examples of hybrids with a detachable keyboard design, which do not fall in the category of 2-in-1s. A rugged laptop is designed to reliably operate in harsh usage conditions such as strong vibrations, extreme temperatures, and wet or dusty environments. Rugged laptops are bulkier, heavier, and much more expensive than regular laptops, and thus are seldom seen in regular consumer use. The basic components of laptops function identically to their desktop counterparts. Traditionally they were miniaturized and adapted to mobile use, The design restrictions on power, size, and cooling of laptops limit
2300-486: A regulated current source that tapers as the battery reaches fully charged voltage. Charging a battery incorrectly can damage a battery; in extreme cases, batteries can overheat, catch fire, or explosively vent their contents. Battery charging and discharging rates are often discussed by referencing a "C" rate of current. The C rate is that which would theoretically fully charge or discharge the battery in one hour. For example, trickle charging might be performed at C/20 (or
2392-483: A resistive voltage drop that is greater than the cell's forward emf . This results in the reversal of the cell's polarity while the current is flowing. The higher the required discharge rate of a battery, the better matched the cells should be, both in the type of cell and state of charge, in order to reduce the chances of cell reversal. In some situations, such as when correcting NiCd batteries that have been previously overcharged, it may be desirable to fully discharge
2484-485: A small niche market , mostly for specialized field applications, such as in the military, for accountants, or travelling sales representatives. As portable computers evolved into modern laptops, they became widely used for a variety of purposes. The history of the laptop follows closely behind the development of the personal computer itself. A "personal, portable information manipulator" was imagined by Alan Kay at Xerox PARC in 1968, and described in his 1972 paper as
2576-493: A standard for memory cards in PCs. The specification for PCMCIA type I cards, later renamed PC Cards, was first released in 1990. Displays reached 640x480 ( VGA ) resolution by 1988 ( Compaq SLT/286 ), and color screens started becoming a common upgrade in 1991, with increases in resolution and screen size occurring frequently until the introduction of 17" screen laptops in 2003. Hard drives started to be used in portables, encouraged by
2668-535: A terminal voltage that does not decline rapidly until nearly exhausted. This terminal voltage drop complicates the design of power electronics for use with ultracapacitors. However, there are potential benefits in cycle efficiency, lifetime, and weight compared with rechargeable systems. China started using ultracapacitors on two commercial bus routes in 2006; one of them is route 11 in Shanghai . Flow batteries , used for specialized applications, are recharged by replacing
2760-587: A type of portable computer that was smaller and lighter than mainstream laptops of the time, but has since come to mean the same thing and no longer refers to any specific size. Laptops are used in a variety of settings, such as at work (especially on business trips ), in education , for playing games , web browsing , for personal multimedia , and for general home computer use. They can run on both AC power and rechargable battery packs and can be folded shut for convenient storage and transportation, making them suitable for mobile use . Laptops combine many of
2852-485: A wide range of CPUs designed for laptops available from both Intel , AMD , and other manufacturers. On non- x86 architectures, Motorola and IBM produced the chips for the former PowerPC -based Apple laptops ( iBook and PowerBook ). Between around 2000 to 2014, most full-size laptops had socketed, replaceable CPUs; on thinner models, the CPU was soldered on the motherboard and was not replaceable or upgradable without replacing
Cloudbook - Misplaced Pages Continue
2944-409: Is a stub . You can help Misplaced Pages by expanding it . Laptop A laptop computer or notebook computer , also known as a laptop or notebook , is a small, portable personal computer (PC). Laptops typically have a clamshell form factor with a flat-panel screen on the inside of the upper lid and an alphanumeric keyboard and pointing device on the inside of the lower lid. Most of
3036-398: Is a concept for a laptop that can be easily disassembled. The terms laptop and notebook both trace their origins to the early 1980s, coined to describe portable computers in a size class smaller than the contemporary mainstream units (so-called "luggables" ) but larger than pocket computers . The etymologist William Safire traced the origin of laptop to some time before 1984;
3128-416: Is a refinement of lithium ion technology by Excellatron. The developers claim a large increase in recharge cycles to around 40,000 and higher charge and discharge rates, at least 5 C charge rate. Sustained 60 C discharge and 1000 C peak discharge rate and a significant increase in specific energy , and energy density. lithium iron phosphate batteries are used in some applications. UltraBattery ,
3220-400: Is already in place for the product. The potassium-ion battery delivers around a million cycles, due to the extraordinary electrochemical stability of potassium insertion/extraction materials such as Prussian blue . The sodium-ion battery is meant for stationary storage and competes with lead–acid batteries. It aims at a low total cost of ownership per kWh of storage. This is achieved by
3312-413: Is considered fast charging. A battery charger system will include more complex control-circuit- and charging strategies for fast charging, than for a charger designed for slower recharging. The active components in a secondary cell are the chemicals that make up the positive and negative active materials, and the electrolyte . The positive and negative electrodes are made up of different materials, with
3404-476: Is mounted, although, as of 2021, an increasing number of models use memory soldered to the motherboard, either alongside SO-DIMM slots or without any slots and soldering all memory to the motherboard, but a new form factor, the CAMM module , is slated to fix the size and timing limitation. Before 2000, most laptops used proprietary memory modules if their memory was upgradable. In the early 2010s, high end laptops such as
3496-429: Is no clear dividing line in minimum or maximum size. Machines small enough to be handheld (screens in the 6–8" range) can be marketed either as very small laptops or "handheld PCs", while the distinction between the largest laptops and "All-in-One" desktops is whether they fold for travel. Having a higher resolution display allows more items to fit onscreen at a time, improving the user's ability to multitask, although, at
3588-427: Is no longer available to participate in the next discharge cycle. Sealed batteries may lose moisture from their liquid electrolyte, especially if overcharged or operated at high temperature. This reduces the cycling life. Recharging time is an important parameter to the user of a product powered by rechargeable batteries. Even if the charging power supply provides enough power to operate the device as well as recharge
3680-430: Is not unknown as of 2022, but since around 2010, the practice has been restricted to small-volume gaming models. Laptop CPUs are rarely able to be overclocked ; most use locked processors. Even on gaming models where unlocked processors are available, the cooling system in most laptops is often very close to its limits and there is rarely headroom for an overclocking–related operating temperature increase. On most laptops,
3772-576: The Socket G2 , but many laptops use processors that are soldered to the motherboard. Many laptops come with RAM and storage that is soldered to the motherboard and cannot be easily replaced. This restriction is one of the major differences between laptops and desktop computers, because the large " tower " cases used in desktop computers are designed so that new motherboards , hard disks , sound cards , RAM , and other components can be added. Memory and storage can often be upgraded with some disassembly, but with
Cloudbook - Misplaced Pages Continue
3864-513: The flip form factor appeared in the early 1980s. The Dulmont Magnum was released in Australia in 1981–82, but was not marketed internationally until 1984–85. The US$ 8,150 (equivalent to $ 25,730 in 2023) GRiD Compass 1101 , released in 1982, was used at NASA and by the military , among others. The Sharp PC-5000 , the Ampere WS-1 , and Gavilan SC were released between 1983 and 1985. The Toshiba T1100 won acceptance by PC experts and
3956-496: The input/output components and capabilities of a desktop computer into a single unit, including a display screen (usually 11–17 in or 280–430 mm in diagonal size), small speakers, a keyboard, and a pointing device (namely compact ones such as touchpads or pointing sticks ). Hardware specifications may vary significantly between different types, models, and price points . Design elements, form factors, and construction can also vary significantly between models depending on
4048-575: The " Dynabook ". The IBM Special Computer APL Machine Portable (SCAMP) was demonstrated in 1973. This prototype was based on the IBM PALM processor . The IBM 5100 , the first commercially available portable computer , appeared in September 1975, and was based on the SCAMP prototype. As 8-bit CPU machines became widely accepted, the number of portables increased rapidly. The first "laptop-sized notebook computer"
4140-450: The 1970s introduction of portable computers, their forms have changed significantly, spawning a variety of visually and technologically differing subclasses. Excepting distinct legal trademark around terms (notably Ultrabook ), hard distinctions between these classes were rare, and their usage has varied over time and between sources. Since the late 2010s, more specific terms have become less commonly used, with sizes distinguished largely by
4232-427: The 1980s using red plasma displays could only be used when connected to AC power, and had a built in power supply. The development of memory cards was driven in the 1980s by the need for a floppy-disk-drive alternative, having lower power consumption, less weight, and reduced volume in laptops. The Personal Computer Memory Card International Association (PCMCIA) was an industry association created in 1989 to promote
4324-509: The 2011 Samsung 700G7A have passed the 10 GB RAM barrier, featuring 16 GB of RAM. When upgradeable, memory slots are sometimes accessible from the bottom of the laptop for ease of upgrading; in other cases, accessing them requires significant disassembly. Most laptops have two memory slots, although some will have only one, either for cost savings or because some amount of memory is soldered. Some high-end models have four slots; these are usually mobile engineering workstations, although
4416-546: The GPU is integrated into the CPU to conserve power and space. This was introduced by Intel with the Core i-series of mobile processors in 2010, followed by similar AMD APU processors in January 2011. Before that, lower-end machines tended to use graphics processors integrated into the system chipset , while higher-end machines had a separate graphics processor. In the past, laptops lacking
4508-479: The U.S. It has also been subjected to extensive testing in hybrid electric vehicles and has been shown to last more than 100,000 vehicle miles in on-road commercial testing in a courier vehicle. The technology is claimed to have a lifetime of 7 to 10 times that of conventional lead-acid batteries in high rate partial state-of-charge use, with safety and environmental benefits claimed over competitors like lithium-ion. Its manufacturer suggests an almost 100% recycling rate
4600-470: The ability to conceal a hardware keyboard. Keyboards on such devices can be flipped, rotated, or slid behind the back of the chassis, thus transforming from a laptop into a tablet. Hybrids have a keyboard detachment mechanism, and due to this feature, all critical components are situated in the part with the display. 2-in-1s can have a hybrid or a convertible form, often dubbed 2-in-1 detachable and 2-in-1 convertibles respectively, but are distinguished by
4692-459: The ability to run a desktop OS , such as Windows 10 . 2-in-1s are often marketed as laptop replacement tablets . 2-in-1s are often very thin, around 10 millimetres (0.39 in), and light devices with a long battery life. 2-in-1s are distinguished from mainstream tablets as they feature an x86 -architecture CPU (typically a low- or ultra-low-voltage model), such as the Intel Core i5 , run
SECTION 50
#17328526388664784-527: The battery is not constant during charging and discharging. Some types have relatively constant voltage during discharge over much of their capacity. Non-rechargeable alkaline and zinc–carbon cells output 1.5 V when new, but this voltage drops with use. Most NiMH AA and AAA cells are rated at 1.2 V, but have a flatter discharge curve than alkalines and can usually be used in equipment designed to use alkaline batteries . Battery manufacturers' technical notes often refer to voltage per cell (VPC) for
4876-404: The battery is overcharged, the optimal level of charge during storage is typically around 30% to 70%. Depth of discharge (DOD) is normally stated as a percentage of the nominal ampere-hour capacity; 0% DOD means no discharge. As the usable capacity of a battery system depends on the rate of discharge and the allowable voltage at the end of discharge, the depth of discharge must be qualified to show
4968-457: The battery, the device is attached to an external power supply during the charging time. For electric vehicles used industrially, charging during off-shifts may be acceptable. For highway electric vehicles, rapid charging is necessary for charging in a reasonable time. A rechargeable battery cannot be recharged at an arbitrarily high rate. The internal resistance of the battery will produce heat, and excessive temperature rise will damage or destroy
5060-404: The cells from overheating. Battery packs intended for rapid charging may include a temperature sensor that the charger uses to protect the pack; the sensor will have one or more additional electrical contacts. Different battery chemistries require different charging schemes. For example, some battery types can be safely recharged from a constant voltage source. Other types need to be charged with
5152-537: The company's ChromeOS ; called Chromebook , the first models were released in 2011. Chromebook was a massive success for Google and found widespread adoption, especially in educational markets. In the mid-2010s, the term cloudbook came to define a competing platform to Chromebook (a so-called "Chromebook killer"): inexpensive, lightweight laptops, with 32- or 64-GB eMMCs , running a pared-down installation of Microsoft 's Windows , prioritizing web apps while being able to run lightweight local apps. This initiative for
5244-444: The computer's internal hardware is fitted inside the lower lid enclosure under the keyboard, although many modern laptops have a built-in webcam at the top of the screen, and some even feature a touchscreen display. In most cases, unlike tablet computers which run on mobile operating systems , laptops tend to run on desktop operating systems, which were originally developed for desktop computers . The word laptop , modeled after
5336-581: The cost of physical space and portability. Higher-end laptops intended for gaming or professional 3D work still come with dedicated (and in some cases even dual) graphics processors on the motherboard or as an internal expansion card . Since 2011, these almost always involve switchable graphics so that when there is no demand for the higher performance dedicated graphics processor, the more power-efficient integrated graphics processor will be used. Nvidia Optimus and AMD Hybrid Graphics are examples of this sort of system of switchable graphics. Traditionally,
5428-414: The current through the discharged cell. Many battery-operated devices have a low-voltage cutoff that prevents deep discharges from occurring that might cause cell reversal. A smart battery has voltage monitoring circuitry built inside. Cell reversal can occur to a weakly charged cell even before it is fully discharged. If the battery drain current is high enough, the cell's internal resistance can create
5520-660: The day to be used at night). Load-leveling reduces the maximum power which a plant must be able to generate, reducing capital cost and the need for peaking power plants . According to a report from Research and Markets, the analysts forecast the global rechargeable battery market to grow at a CAGR of 8.32% during the period 2018–2022. Small rechargeable batteries can power portable electronic devices , power tools, appliances, and so on. Heavy-duty batteries power electric vehicles , ranging from scooters to locomotives and ships . They are used in distributed electricity generation and in stand-alone power systems . During charging,
5612-465: The earliest attestation of laptop found by the Oxford English Dictionary dates to 1983. The word is modeled after the term desktop , as in desktop computer . Notebook , meanwhile, emerged earlier in 1982 to describe Epson 's HX-20 portable, whose dimensions roughly correspond to a letter -sized pad of paper . Notebooks emerged as their own separate market from laptops with
SECTION 60
#17328526388665704-417: The early 2010s. Optical disc drives became common in full-size laptops around 1997: initially, CD-ROM drives, supplanted by CD-R, then DVD, then Blu-ray drives with writing capability. Starting around 2011, the trend shifted against internal optical drives, and as of 2022, they have largely disappeared, though are still readily available as external peripherals . In 2021, Dell showed Concept Luna, which
5796-763: The higher resolutions on smaller screens, the resolution may only serve to display sharper graphics and text rather than increasing the usable area. Since the introduction of the MacBook Pro with Retina display in 2012, there has been an increase in the availability of "HiDPI" (or high Pixel density ) displays; as of 2022, this is generally considered to be anything higher than 1920 pixels wide. This has increasingly converged around 4K (3840-pixel-wide) resolutions. External displays can be connected to most laptops, with most models supporting at least one. The use of technology such as USB4 (section Alternate Mode partner specifications ). DisplayPort Alt Mode has been utilized to charge
5888-459: The individual cells that make up the battery. For example, to charge a 12 V lead-acid battery (containing 6 cells of 2 V each) at 2.3 VPC requires a voltage of 13.8 V across the battery's terminals. Subjecting a discharged cell to a current in the direction which tends to discharge it further to the point the positive and negative terminals switch polarity causes a condition called cell reversal . Generally, pushing current through
5980-417: The industry. Ultracapacitors are being developed for transportation, using a large capacitor to store energy instead of the rechargeable battery banks used in hybrid vehicles . One drawback of capacitors compared to batteries is that the terminal voltage drops rapidly; a capacitor that has 25% of its initial energy left in it will have one-half of its initial voltage. By contrast, battery systems tend to have
6072-644: The intended use. Examples of specialized models of laptops include 2-in-1 laptops , with keyboards that either be detached or pivoted out of view from the display (often marketed having a "laptop mode"); rugged laptops , for use in construction or military applications ; and low-production-cost laptops such as those from the One Laptop per Child (OLPC) organization, which incorporate features like solar charging and semi-flexible components not found on most laptop computers. Portable computers , which later developed into modern laptops, were originally considered to be
6164-464: The introduction of 3.5" drives in the late 1980s, and became common in laptops starting with the introduction of 2.5" and smaller drives around 1990; capacities have typically lagged behind those of physically larger desktop drives. Resolutions of laptop webcams are 720p (HD), or 480p in lower-end laptops. The earliest-known laptops with 1080p (Full HD) webcams, like the Samsung 700G7C, were released in
6256-428: The late 2000s, SSDs were substantially more expensive than HDDs, but as of 2021 prices on smaller capacity (under 1 terabyte ) drives have converged; larger capacity drives remain more expensive than comparable-sized HDDs. Rechargable A rechargeable battery , storage battery , or secondary cell (formally a type of energy accumulator ), is a type of electrical battery which can be charged, discharged into
6348-579: The low cost, makes it attractive for use in motor vehicles to provide the high current required by automobile starter motors . The nickel–cadmium battery (NiCd) was invented by Waldemar Jungner of Sweden in 1899. It uses nickel oxide hydroxide and metallic cadmium as electrodes . Cadmium is a toxic element, and was banned for most uses by the European Union in 2004. Nickel–cadmium batteries have been almost completely superseded by nickel–metal hydride (NiMH) batteries. The nickel–iron battery (NiFe)
6440-478: The low price and mainstream performance, there is no longer a significant performance difference between laptop and desktop CPUs, but at the high end, the fastest desktop CPUs still substantially outperform the fastest laptop processors, at the expense of massively higher power consumption and heat generation; the fastest laptop processors top out at 56 watts of heat, while the fastest desktop processors top out at 150 watts (and often need water cooling). There has been
6532-560: The mass market as a way to have PC portability. From 1983 onward, several new input techniques were developed and included in laptops, including the touch pad ( Gavilan SC , 1983), the pointing stick (IBM ThinkPad 700 , 1992), and handwriting recognition (Linus Write-Top, 1987). Some CPUs, such as the 1990 Intel i386SL , were designed to use minimum power to increase the battery life of portable computers and were supported by dynamic power management features such as Intel SpeedStep and AMD PowerNow! in some designs. Some laptops in
6624-406: The maximum performance of laptop parts compared to that of desktop components, although that difference has increasingly narrowed. In general, laptop components are not intended to be replaceable or upgradable by the end-user, except for components that can be detached; in the past, batteries and optical drives were commonly exchangeable. Some laptops feature socketed processors with sockets such as
6716-479: The most compact laptops, there may be no upgradeable components at all. The following sections summarize the differences and distinguishing features of laptop components in comparison to desktop personal computer parts. The typical laptop has a screen that, when unfolded, is upright to the user. Laptop screens most commonly employ liquid-crystal display (LCD) technology, although use of OLED panels has risen substantially since 2020. The display interfaces with
6808-921: The motherboard using the embedded DisplayPort protocol via the Low-voltage differential signaling (LVDS) 30 or 40 pin connector. The panels are mainly manufactured by AU Optronics , BOE Technology , LG Display or Samsung Display . Externally, it can be a glossy or a matte (anti-glare) screen. In the past, there was a broader range of marketing terms (both formal and informal) to distinguish between different sizes of laptops. These included Netbooks , subnotebooks , Ultra-mobile PC , and Desktop replacement computers ; these are sometimes still used informally, although they are essentially dead in terms of manufacturer marketing. As of 2021, mainstream consumer laptops tend to come with 11", 13" or 15"-16" screens; 14" models are more popular among business machines. Larger and smaller models are available, but less common – there
6900-428: The motherboard. Since 2015, Intel has not offered new laptop CPU models with pins to be interchangeable, preferring ball grid array chip packages which have to be soldered; and as of 2021, only a few rare models using desktop parts. In the past, some laptops have used a desktop processor instead of the laptop version and have had high-performance gains at the cost of greater weight, heat, and limited battery life; this
6992-500: The number of charge cycles increases, until they are eventually considered to have reached the end of their useful life. Different battery systems have differing mechanisms for wearing out. For example, in lead-acid batteries, not all the active material is restored to the plates on each charge/discharge cycle; eventually enough material is lost that the battery capacity is reduced. In lithium-ion types, especially on deep discharge, some reactive lithium metal can be formed on charging, which
7084-510: The positive active material is oxidized , releasing electrons , and the negative material is reduced , absorbing electrons. These electrons constitute the current flow in the external circuit . The electrolyte may serve as a simple buffer for internal ion flow between the electrodes , as in lithium-ion and nickel-cadmium cells, or it may be an active participant in the electrochemical reaction, as in lead–acid cells. The energy used to charge rechargeable batteries usually comes from
7176-467: The positive electrode is the cathode on discharge and the anode on charge, and vice versa for the negative electrode. The lead–acid battery , invented in 1859 by French physicist Gaston Planté , is the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, its ability to supply high surge currents means that the cells have a relatively large power-to-weight ratio . These features, along with
7268-532: The positive exhibiting a reduction potential and the negative having an oxidation potential. The sum of the potentials from these half-reactions is the standard cell potential or voltage . In primary cells the positive and negative electrodes are known as the cathode and anode , respectively. Although this convention is sometimes carried through to rechargeable systems—especially with lithium-ion cells, because of their origins in primary lithium cells—this practice can lead to confusion. In rechargeable cells
7360-483: The range of 150–260 Wh/kg, batteries based on lithium-sulfur are expected to achieve 450–500 Wh/kg, and can eliminate cobalt, nickel and manganese from the production process. Furthermore, while initially lithium-sulfur batteries suffered from stability problems, recent research has made advances in developing lithium-sulfur batteries that cycle as long as (or longer than) batteries based on conventional lithium-ion technologies. The thin-film battery (TFB)
7452-461: The relationship between time and discharge rate is described by Peukert's law ; a lead-acid cell that can no longer sustain a usable terminal voltage at a high current may still have usable capacity, if discharged at a much lower rate. Data sheets for rechargeable cells often list the discharge capacity on 8-hour or 20-hour or other stated time; cells for uninterruptible power supply systems may be rated at 15-minute discharge. The terminal voltage of
7544-474: The release of the NEC UltraLite in 1988. Notebooks and laptops continued to occupy distinct market segments into the mid-1990s, but ergonomic considerations and customer preference for larger screens soon led to notebooks converging with laptops in the late 1990s. Today, the terms laptop and notebook are synonymous, with laptop being the more common term in most English-speaking territories. Since
7636-590: The risk is acceptable. Lithium-ion polymer batteries (LiPo) are light in weight, offer slightly higher energy density than Li-ion at slightly higher cost, and can be made in any shape. They are available but have not displaced Li-ion in the market. A primary use is for LiPo batteries is in powering remote-controlled cars, boats and airplanes. LiPo packs are readily available on the consumer market, in various configurations, up to 44.4 V, for powering certain R/C vehicles and helicopters or drones. Some test reports warn of
7728-595: The risk of fire when the batteries are not used in accordance with the instructions. Independent reviews of the technology discuss the risk of fire and explosion from lithium-ion batteries under certain conditions because they use liquid electrolytes. ‡ citations are needed for these parameters Several types of lithium–sulfur battery have been developed, and numerous research groups and organizations have demonstrated that batteries based on lithium sulfur can achieve superior energy density to other lithium technologies. Whereas lithium-ion batteries offer energy density in
7820-432: The size of mainstream laptops has gone down and their capabilities have gone up; except for niche models, laptop sizes tend to be distinguished by the size of the screen, and for more powerful models, by any specialized purpose the machine is intended for, such as a " gaming laptop " or a " mobile workstation " for professional use. The latest trend of technological convergence in the portable computer industry spawned
7912-511: The size of the screen. There were in the past a number of marketing categories for smaller and larger laptop computers; these included "notebook" and " subnotebook " models, low cost " netbooks ", and " ultra-mobile PCs " where the size class overlapped with devices like smartphone and handheld tablets , and " Desktop replacement " laptops for machines notably larger and heavier than typical to operate more powerful processors or graphics hardware . All of these terms have fallen out of favor as
8004-418: The system RAM on laptops (as well as on desktop computers) was physically separate from the graphics memory used by the GPU. Apple's M series SoCs feature a unified pool of memory for both the system and the GPU; this approach can produce substantial efficiency gains for some applications but comes at the cost of eGPU support. Since around the year 2000, most laptops have used SO-DIMM slots in which RAM
8096-596: The technology to reduce cost, weight, and size, and increase lifetime. Older rechargeable batteries self-discharge relatively rapidly and require charging before first use; some newer low self-discharge NiMH batteries hold their charge for many months, and are typically sold factory-charged to about 70% of their rated capacity. Battery storage power stations use rechargeable batteries for load-leveling (storing electric energy at times of low demand for use during peak periods) and for renewable energy uses (such as storing power generated from photovoltaic arrays during
8188-491: The term desktop (as in desktop computer ), refers to the fact that the computer can be practically placed on the user's lap ; while the word notebook refers to most laptops sharing a form factor with paper notebooks . As of 2024 , in American English , the terms laptop and notebook are used interchangeably; in other dialects of English , one or the other may be preferred. The term notebook originally referred to
8280-579: The way it is to be measured. Due to variations during manufacture and aging, the DOD for complete discharge can change over time or number of charge cycles . Generally a rechargeable battery system will tolerate more charge/discharge cycles if the DOD is lower on each cycle. Lithium batteries can discharge to about 80 to 90% of their nominal capacity. Lead-acid batteries can discharge to about 50–60%. While flow batteries can discharge 100%. If batteries are used repeatedly even without mistreatment, they lose capacity as
8372-476: Was also developed by Waldemar Jungner in 1899; and commercialized by Thomas Edison in 1901 in the United States for electric vehicles and railway signalling . It is composed of only non-toxic elements, unlike many kinds of batteries that contain toxic mercury, cadmium, or lead. The nickel–metal hydride battery (NiMH) became available in 1989. These are now a common consumer and industrial type. The battery has
8464-798: Was the Epson HX-20 , invented (patented) by Suwa Seikosha 's Yukio Yokozawa in July 1980, introduced at the COMDEX computer show in Las Vegas by Japanese company Seiko Epson in 1981, and released in July 1982. It had an LCD screen, a rechargeable battery, and a calculator-size printer, in a 1.6 kg (3.5 lb) chassis, the size of an A4 notebook . It was described as a "laptop" and "notebook" computer in its patent. Both Tandy/RadioShack and Hewlett-Packard (HP) also produced portable computers of varying designs during this period. The first laptops using
#865134