A power bank or battery bank is a portable device that stores energy in its battery. Power banks are made in various sizes and typically based on lithium ion batteries. A power bank contains battery cells and a voltage converter circuitry. The internal DC-DC converter manages battery charging and converts the battery stack's voltage to the desired output voltage. The advertised capacity on the product in many instances is based on the capacity of the internal cells, however the theoretical mAh available to output depends on the output voltage. The conversion circuit has some energy losses, so the actual output is less than theoretical. [1] [2] The theoretical mAh of a 3.7 V battery power bank with 5 V output is 74% of the battery mAh rating. The RavPower RP-PB41 with advertised capacity of 26,800 mAh that was evaluated in the journal has a theoretical capacity is 19,832 mAh, although the delivered capacity was 15,682 mAh, 78% of theoretical value. Authors attributed the difference to internal resistance in battery and converter losses. [2] The circuit board can contain additional features such as over discharge protection, automatic shut off and charge level indication LEDs. [3] [4] Power banks may be able to detect a connection and power on automatically. If the current load is under a model-specific threshold for a specific duration, a power bank may power down automatically. [5]
Some power banks are able to deliver power wirelessly, some are equipped with an LED flashlight for casual near-distance illumination when necessary, and some have a pass-through charging feature which allows providing power through their USB ports while being charged themselves simultaneously. [6] Some larger power banks have DC connectors (or barrel connectors) for higher power demands such as laptop computers.
Battery cases are small power banks attached to the rear side of a mobile phone like a case. Power may be delivered through the USB charging ports, [7] or wirelessly. [8] Battery cases also exist in the form of a camera grip accessory, as was for the Nokia Lumia 1020. [9] For mobile phones with removable rear cover, extended batteries exist. These are larger internal batteries attached with a dedicated, more spacious rear cover replacing the default one. A disadvantage is incompatibility with other phone cases while attached. [10]
In some parts of the world, there are kiosk based power bank rental or subscription services. Customers pay for the use of power bank for a specified period of time and return the depleted power bank to the kiosk. [11] In one case with a brand called FuelRod, it was sold at an elevated price at various amusement parks with the understanding that they get a perk of free exchange at participating locations. [12] FuelRod moved to discontinue the free exchange in 2019 and resulted in a class-action lawsuit reaching a settlement that early adopters would be grandfathered to free exchange privileges. [13]
The examples and perspective in this section deal primarily with the United States and do not represent a worldwide view of the subject.(April 2024) |
Per US Federal Aviation Administration regulations, power banks in the United States are not allowed in checked-in luggage. Power banks up to 100 Wh are allowed as carry-on and those 101 Wh to 160 Wh are allowed with airline approval. [14]
A lithium-ion or Li-ion battery is a type of rechargeable battery that uses the reversible intercalation of Li+ ions into electronically conducting solids to store energy. In comparison with other commercial rechargeable batteries, Li-ion batteries are characterized by higher specific energy, higher energy density, higher energy efficiency, a longer cycle life, and a longer calendar life. Also noteworthy is a dramatic improvement in lithium-ion battery properties after their market introduction in 1991: within the next 30 years, their volumetric energy density increased threefold while their cost dropped tenfold.
A rechargeable battery, storage battery, or secondary cell, is a type of electrical battery which can be charged, discharged into 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.
An automotive battery, or car battery, is a rechargeable battery that is used to start a motor vehicle. Its main purpose is to provide an electric current to the electric-powered starting motor, which in turn starts the chemically-powered internal combustion engine that actually propels the vehicle. Once the engine is running, power for the car's electrical systems is still supplied by the battery, with the alternator charging the battery as demands increase or decrease.
The AA battery is a standard size single cell cylindrical dry battery. The IEC 60086 system calls the size R6, and ANSI C18 calls it 15. It is named UM-3 by JIS of Japan. Historically, it is known as D14, U12 – later U7, or HP7 in official documentation in the United Kingdom, or a pen cell.
A battery pack is a set of any number of (preferably) identical batteries or individual battery cells. They may be configured in a series, parallel or a mixture of both to deliver the desired voltage and current. The term battery pack is often used in reference to cordless tools, radio-controlled hobby toys, and battery electric vehicles.
A battery charger, recharger, or simply charger, is a device that stores energy in an electric battery by running current through it. The charging protocol—how much voltage, current, for how long and what to do when charging is complete—depends on the size and type of the battery being charged. Some battery types have high tolerance for overcharging after the battery has been fully charged and can be recharged by connection to a constant voltage source or a constant current source, depending on battery type.
The lithium iron phosphate battery or LFP battery is a type of lithium-ion battery using lithium iron phosphate as the cathode material, and a graphitic carbon electrode with a metallic backing as the anode. Because of their low cost, high safety, low toxicity, long cycle life and other factors, LFP batteries are finding a number of roles in vehicle use, utility-scale stationary applications, and backup power. LFP batteries are cobalt-free. As of September 2022, LFP type battery market share for EVs reached 31%, and of that, 68% were from EV makers Tesla and BYD alone. Chinese manufacturers currently hold a near monopoly of LFP battery type production. With patents having started to expire in 2022 and the increased demand for cheaper EV batteries, LFP type production is expected to rise further and surpass lithium nickel manganese cobalt oxides (NMC) type batteries in 2028.
Lithium iron phosphate or lithium ferro-phosphate (LFP) is an inorganic compound with the formula LiFePO
4. It is a gray, red-grey, brown or black solid that is insoluble in water. The material has attracted attention as a component of lithium iron phosphate batteries, a type of Li-ion battery. This battery chemistry is targeted for use in power tools, electric vehicles, solar energy installations and more recently large grid-scale energy storage.
A nanowire battery uses nanowires to increase the surface area of one or both of its electrodes, which improves the capacity of the battery. Some designs, variations of the lithium-ion battery have been announced, although none are commercially available. All of the concepts replace the traditional graphite anode and could improve battery performance. Each type of nanowire battery has specific advantages and disadvantages, but a challenge common to all of them is their fragility.
The lithium-titanate or lithium-titanium-oxide (LTO) battery is a type of rechargeable battery which has the advantage of being faster to charge than other lithium-ion batteries but the disadvantage is a much lower energy density.
A solid-state battery is an electrical battery that uses a solid electrolyte for ionic conductions between the electrodes, instead of the liquid or gel polymer electrolytes found in conventional batteries. Solid-state batteries theoretically offer much higher energy density than the typical lithium-ion or lithium polymer batteries.
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.
Sodium-ion batteries (NIBs, SIBs, or Na-ion batteries) are several types of rechargeable batteries, which use sodium ions (Na+) as their charge carriers. In some cases, its working principle and cell construction are similar to those of lithium-ion battery (LIB) types, but it replaces lithium with sodium as the intercalating ion. Sodium belongs to the same group in the periodic table as lithium and thus has similar chemical properties. However, in some cases, such as aqueous batteries, SIBs can be quite different from LIBs.
Aluminium-ion batteries are a class of rechargeable battery in which aluminium ions serve as charge carriers. Aluminium can exchange three electrons per ion. This means that insertion of one Al3+ is equivalent to three Li+ ions. Thus, since the ionic radii of Al3+ (0.54 Å) and Li+ (0.76 Å) are similar, significantly higher numbers of electrons and Al3+ ions can be accepted by cathodes with little damage. Al has 50 times (23.5 megawatt-hours m-3) the energy density of Li and is even higher than coal.
The Nokia Lumia 820 is a smartphone designed, developed and marketed by Nokia. It is the successor to the Lumia 800 and is one of the first Nokia phones to implement Windows Phone 8 alongside the Nokia Lumia 920. Although sharing a similar appearance with the Lumia 800, the Lumia 820 is a major overhaul over its predecessor, sporting a 4.3 inches (110 mm) diagonal OLED display with scratch resistant glass, though lacking Gorilla Glass protection, 1.5 GHz dual-core processor, and an 8.7-megapixel camera. The phone will come with LTE connectivity and a wireless-charging option. The 820 is the first Nokia Windows Phone OS based smartphone to embed a microSD card slot.
The Nokia Lumia 720 is a Windows Phone 8 device manufactured by Nokia. It was announced at the 2013 Mobile World Congress.
The Nokia Lumia 1520 was a flagship Windows Phone phablet smartphone designed and produced by Finnish telecommunications manufacturer Nokia in partnership with American software manufacturer Microsoft. The device was first announced at the Nokia World event on 22 October 2013 in Abu Dhabi, alongside its mid-range phablet stablemate the Nokia Lumia 1320 and Nokia's 10.1 inch Windows RT tablet the Nokia Lumia 2520. Until its discontinuation in the United States on 7 April 2015 the phone served as the flagship device for Nokia's Lumia Series and Microsoft's mobile effort. On 6 October 2015 Microsoft officially announced its flagship phablet successor, the Microsoft Lumia 950 XL, with availability sometime in November 2015.
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 reducing cost.
The lithium nickel cobalt aluminium oxides (abbreviated as Li-NCA, LNCA, or NCA) are a group of mixed metal oxides. Some of them are important due to their application in lithium ion batteries. NCAs are used as active material in the positive electrode (which is the cathode when the battery is discharged). NCAs are composed of the cations of the chemical elements lithium, nickel, cobalt and aluminium. The compounds of this class have a general formula LiNixCoyAlzO2 with x + y + z = 1. In case of the NCA comprising batteries currently available on the market, which are also used in electric cars and electric appliances, x ≈ 0.8, and the voltage of those batteries is between 3.6 V and 4.0 V, at a nominal voltage of 3.6 V or 3.7 V. A version of the oxides currently in use in 2019 is LiNi0.84Co0.12Al0.04O2.
Alkaline sulfur liquid battery (SLIQ) is a liquid battery which consists of only one rechargeable liquid and a technology which can be used for grid storage.