A valve regulated lead–acid (VRLA) battery, commonly known as a sealed lead–acid (SLA) battery, is a type of lead–acid battery characterized by a limited amount of electrolyte ("starved" electrolyte) absorbed in a plate separator or formed into a gel; proportioning of the negative and positive plates so that oxygen recombination is facilitated within the cell; and the presence of a relief valve that retains the battery contents independent of the position of the cells.
There are two primary types of VRLA batteries, absorbent glass mat (AGM) and gel cell (gel battery). Gel cells add silica dust to the electrolyte, forming a thick putty like gel. AGM (absorbent glass mat) batteries feature fiberglass mesh between the battery plates which serves to contain the electrolyte and separate the plates. Both types of VRLA batteries offer advantages and disadvantages compared to flooded vented lead–acid (VLA) batteries or each other.
Due to their construction, the gel cell and AGM types of VRLA can be mounted in any orientation, and do not require constant maintenance. The term "maintenance free" is a misnomer as VRLA batteries still require cleaning and regular functional testing. They are widely used in large portable electrical devices, off-grid power systems and similar roles, where large amounts of storage are needed at a lower cost than other low maintenance technologies like lithium ion.
The first lead–acid gel battery was invented by Elektrotechnische Fabrik Sonneberg in 1934. The modern gel or VRLA battery was invented by Otto Jache of Sonnenschein in 1957. The first AGM cell was the Cyclon, patented by Gates Rubber Corporation in 1972 and now produced by EnerSys.
The cyclon is a spiral wound cell with thin lead foil electrodes. A number of manufacturers seized on the technology to implement it in cells with conventional flat plates. In the mid 1980s, two UK companies, Chloride and Tungstone, simultaneously introduced ten year life AGM batteries in capacities up to 400 Ah, stimulated by a British Telecom specification for batteries for support of new digital exchanges.
Cette page est générée automatiquement et peut contenir des informations qui ne sont pas correctes, complètes, à jour ou pertinentes par rapport à votre recherche. Il en va de même pour toutes les autres pages de ce site. Veillez à vérifier les informations auprès des sources officielles de l'EPFL.
An electric vehicle battery (EVB, also known as a traction battery) is a rechargeable battery used to power the electric motors of a battery electric vehicle (BEV) or hybrid electric vehicle (HEV). Electric vehicle batteries differ from starting, lighting, and ignition (SLI) batteries, as they are typically lithium-ion batteries that are designed for high power-to-weight ratio and energy density. Smaller, lighter batteries are desirable because they reduce the weight of the vehicle and therefore improve its performance.
Une pile électrique, couramment dénommée « pile », est un dispositif électrochimique qui produit de l'électricité en convertissant de l'énergie chimique en énergie électrique grâce à une réaction d'oxydoréduction. Ce système électrochimique a été inventé par le scientifique italien Alessandro Volta en empilant des couches de deux métaux séparées par des feutres imbibés d'acide. Le Bureau international des poids et mesures choisit de nommer l'unité de potentiel électrique le volt, en référence à Volta.
La collecte et le recyclage des batteries est l'activité visant à récupérer les métaux toxiques, rares, précieux ou économiquement valorisables présents dans les batteries, ou d'autres composants des batteries (acides et plastique notamment). Il vise aussi à réduire la quantité de batteries retrouvée dans les ordures ménagères (en dépit du tri sélectif) quand et là où il existe, et en dépit des interdictions et logos précisant que les piles et batteries ne doivent pas être jetées avec les ordures ménagères.
This course aims at familiarizing the student with state of the art applications of electrochemistry in materials science and technology as well as material requirements for electrochemical engineerin
Explore les bases de l'électromagnétisme, la loi d'Ohm, la loi de Lenz, et la loi de Faraday, éteignant la lumière sur les appareils électromagnétiques.
Couvre les exercices liés aux condensateurs planaires avec des plaques carrées et un ressort, en évaluant les positions d'équilibre et l'effet du changement de polarité de la batterie.
Using batteries of visual tests, most studies have found that there are only weak correlations between performance levels of tests in healthy young adults. Factor analysis has confirmed these results. This means that a participant excelling in one test may ...
In an era where portable electronic devices are indispensable for a wide range of activities, the need for displays that provide both long-lasting battery life and excellent visibility in different lighting conditions is increasingly important. Emissive di ...
A user’s benefit from the energy stored in a battery over its lifetime depends on the time-varying characteristics of the battery, which are in turn affected by the chosen usage behavior. Both the capacity shrinkage and the number of lifetime cycles are st ...