Battery dictionary

The acid density describes the ratio between acid and water in a battery. When the battery is discharged, the acid density decreases due to chemical reactions and increases as soon as the battery is recharged. Sulphate ions pass back into the electrolyte.

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The use of activated carbon in batteries makes them fast-chargeable and cycle-resistant for short cycles (PSoC = Partial State of Charge). The material incorporated into the negative plates increases the battery's conductivity and ability to draw current.

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The active mass is the material in the electrodes that absorbs electrical energy electrochemically during charging and releases it during discharging.

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The abbreviation stands for "Absorbent Glass Mat" and refers to a special technology for lead-acid batteries. The fleece encloses the liquid electrolyte. Thus, the battery has a leak-proof design. The positive and negative lead plates (anodes and cathodes) are each separated by a glass fibre fleece - AGM thus acts as an electrolyte container and separator, so to speak. This allows the battery to be used flexibly - it can also be installed in a horizontal position. This "pancake" arrangement is optimal for the use of AGM. The binding of the acid in the fleece also makes AGM batteries low-maintenance - no need to top up with water or check the electrolyte level. The advantages of this technology: better performance and longer life. AGM batteries are mainly used for emergency power supply of critical infrastructures such as the energy industry due to their fast high-current discharge capability.

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Alloy refers to the composition of several metals or one metal and one non-metal. Electrodes in batteries are often alloys.

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Current can flow in two different ways: either the electrons move in the same direction, or they frequently change their direction of movement. The latter refers to alternating current

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An ampere is a unit of measurement for electric current. It indicates how much electric current flows through a conductor.

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This term is a unit of measurement for electrical charge. An Ah denotes the amount of current that flows through a conductor (e.g. metal) within one hour. It is a product of the amperage (in amperes) and the length of time (in hours) that the current flows. The capacity of a battery is usually given in Ah.

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The anode is the place of oxidation in a battery. It emits electrons, which then travel to the cathode. Driven by the voltage difference between the anode and the cathode, the electrons perform electrical work when they pass the consumer (e.g. a light bulb) and thus make the bulb light up. In a secondary cell, either of the two electrodes can become the anode, depending on the direction of the current flow.

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Backup batteries are used, for example, in critical infrastructure to provide power in the event of a power failure until conventional power grids are restored. Emergency power batteries are mainly found in connection with hospitals, telecommunication systems and data centres.

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Differences in cell voltages can occur between the individual cells of a battery. The reason for this is a different internal resistance and a resulting different charge assumption. The different resistances are caused by natural chemical processes within the battery. Therefore, a regular equalisation charge (approx. 1x/year) is necessary to bring the cells back to a uniform voltage level. In this way, the performance of the battery can be maintained and the service life extended.

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In an energy supply system, electricity generation and consumption must always be approximately equal. If too much is produced or consumed, balancing energy must be used to compensate: the excess electricity produced is stored or the additional electricity required is fed in - e.g. from a battery.

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VRLA stands for Valve Regulated Lead Acid Battery. It refers to a lead-acid battery in which the electrolyte is fixed in a gel or a micro glass fleece (AGM). The battery is sealed and equipped with safety valves. Due to internal recombination, these batteries are maintenance-free in terms of refilling with water.

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Vented batteries allow access to the inside of the cells - this happens mainly for maintenance. Through openings in the lid, water can be easily refilled and the electrolyte level and density can be checked.

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A battery is a storage device for electrical energy. When needed, it serves as a power source - until the stored energy is used up. It consists of an electrolyte, an anode, a cathode and a separator.

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A battery controller is a communication unit that is installed on the battery. The unit can provide real-time data about various parameters of the battery, such as the state of charge, the general battery condition or the temperature of the battery. The controller transmits this data to monitoring systems, the charger or to the user's PC. This way, the user always has a good overview of his batteries and can intervene in time in case of malfunctions.

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Battery maintenance, which by the way should be carried out regularly, includes above all: measuring cell voltages and acid densities, refilling water, checking cell connectors, cell plugs and end connections. Detailed instructions on how to maintain your battery can be found in the HOPPECKE manual.

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A battery rack is a metal or wooden structure for housing individual battery cells or blocks in order to interconnect them in a maintenance-friendly way to form an energy storage system. There are also earthquake-proof racks that allow a form-fit installation of the cells or blocks and can thus withstand the increased seismic loads (e.g. in nuclear power plants).

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The capacity of a battery is the amount of electricity that can be extracted per unit of time (Ah) under the respective conditions. It is essentially dependent on discharge current, discharge voltage and temperature. Calculation: C = I x t (current x discharge time)

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The actual capacity is the capacity that can actually be removed under specified conditions (e.g. current, temperature, electrolyte level).

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The nominal capacity describes the current-carrying capacity of batteries or rechargeable batteries and is usually given in Ah. The nominal capacity is calculated from the product of current and time in hours and enables a factual comparison of different batteries.

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The cathode is the electrode in the battery where the chemical reduction takes place.

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The cell is a component of the battery. Each cell can have up to 2V (lead-acid cells) - so 12 cells are needed for a 24 V battery. The individual cells are connected in series so that the desired system voltage is set.

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Over time, batteries have been equipped with cell lids with one or more openings to minimise water evaporation. Plugs with different functions are inserted into these openings to ensure a mechanical but not gas-tight closure of the cell.

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When forklift fleets operate in multiple shifts, battery replacement is often necessary to guarantee continuous forklift operation. With exchange trolleys, the often very heavy batteries can be lifted out of the truck, moved to the charging station and exchanged with charged batteries. This ergonomically supports the safety at work of the employees and enables a battery change without much time expenditure.

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Corrosion refers to the chemical process in which substances are corroded by oxidation. Ex: The steel that keeps bridges stable corrodes after a certain time - the stable metal structure can then no longer be maintained and the bridge must be renovated to avoid collapse. The lead used in batteries to manufacture the components forms a passive protective layer of lead monoxide when attacked by corrosion, which greatly inhibits or slows down further corrosion. This prolongs the life of the battery.

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One coulomb denotes the amount of electricity transported by a current of one ampére within one second.

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This term refers to the facilities, systems and services in a country or region that must be able to function even in an emergency, because a failure would have drastic effects on society. This includes, for example, energy supply, telecommunications, (waste) water systems and IT networks.

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The more cycle-resistant a battery is, the more charge and discharge cycles it can go through without any significant loss of performance. This is particularly important for rechargeable batteries that are used and charged on a daily basis - for example, traction batteries for industrial trucks in large logistics centres. Good cycle stability also means less maintenance and a longer service life.

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A colocation data centre is a data centre that is used by several customers to run their own servers in a secure environment. The customers only rent the space, power supply, cooling and internet connection, but the hardware is theirs. A colocation data centre offers advantages such as high availability, scalability and cost efficiency.

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Deep discharge exceeds the permissible capacity drain, so it should be avoided. The condition produces a greatly reduced acid density and has a negative effect on the chargeability of the batteries. In extreme cases, the polarity of the two electrodes may be reversed.

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Efficiency refers to the degree of output generated from a given input - i.e. the ratio of energy supplied and energy that can actually be used. Efficiency can be used to show how efficiently a machine converts energy. High efficiency is desirable because it reduces energy consumption, lowers the cost of energy and maximises the efficiency of machines.

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Current can flow in two different ways: either the electrons move in the same direction, or they frequently change their direction of movement. The former refers to direct current; the electrodes flow from the negative to the positive pole without significant interference. Direct current is the type of current provided by batteries and accumulators.

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The discharge voltage refers to the battery voltage that occurs during discharge with the associated discharge current.

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The discharge performance of a battery describes its behaviour during discharge - i.e. how well a battery can release the stored current again. This is important for the reliable functioning of the connected consumers (e.g. a forklift).

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Electrodes or the plates consist of a carrier material (e.g. lead-antimony alloy or lead-calcium alloy) and the active mass, the latter being the actual energy storage.

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Electrolysis refers to the decomposition of water into oxygen and hydrogen. This happens during the charging of a battery through the supply of electric current. In unsealed batteries, electrolysis makes regular water refilling necessary because oxygen and hydrogen partially escape after decomposition. Sealed batteries do not need water refilling because the oxygen ions are "forced" by internal recombination to migrate to the negative plate and combine there with hydrogen ions freely available in the electrolyte to form water.

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Electrolyte is a central component of a battery. It is an imprecise collective term for media that are electrically conductive because of the electrically charged atoms or molecules (ions) they contain. These are usually liquids: In lead-acid batteries, for example, it is sulphuric acid diluted with water.

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The Electrolyte circulation is, so to speak, the antidote to electrolyte stratification in a lead-acid battery. Air is pumped into the battery through one air tube per cell - the air bubbles that then rise "entrain" the ions and thus ensure that the electrolyte stratification is eliminated. Electrolyte circulation using air is so efficient that the recharging time is considerably shorter.

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When a lead-acid cell is charged, acid with a high density is produced in the plates and released into the electrolyte with a lower density, where it then sinks towards the bottom of the cell. If this acid is not mixed by increasing the charging voltage (gassing the battery), shaking or electrolyte circulation, the battery will be permanently damaged.

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Electrons are negatively charged particles. In a battery, they form the electric current when discharging by flowing from the negative to the positive terminal.

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The energy density describes how much energy can be stored in a certain volume of the battery. A higher energy density means that the battery can store more energy per kilogram - this increases, for example, the range that a vehicle can drive with the battery.

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Renewable energies (RE) or regenerative energies are energy sources that are practically inexhaustible in the human time horizon for sustainable energy supply or are renewed relatively quickly. This means that finite resources such as wood/oil/gas can be conserved.

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The enhanced Stability Standard (ESS) technology is used in all HOPPECKE products in AGM (Absorbent Glass Matt) design and represents a further development of this basic technology. Gel additives in the electrolyte increase resistance to thermal runaway, increase charge acceptance and ensure more uniform voltage behaviour of the battery. This leads to a longer service life and reduced service costs: in sum, optimised life cycle costs.

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When charging, an accumulator strives to draw the current determined by its internal resistance. When fast charging, the battery is charged with a multiple of the battery's rated current to shorten the charging time - this is often done with traction batteries. Fast charging causes the battery to heat up noticeably and thus promotes ageing.

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The type of nickel-cadmium batteries is based on the unique fibre structure technology. Here, the active material is placed in a fleece consisting of nickel-plated plastic fibres, which creates a very good and stable electrochemical bond between the components. The chemical properties give the battery a long shelf life and problem-free usability even under extreme temperatures or shocks - they are therefore most frequently used in trains for on-board and emergency power supply.

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In this technology, the electrolyte is fixed (it solidifies) by adding silica to the sulphuric acid. This technology is only used in sealed batteries. The big advantage: no electrolyte stratification takes place.

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Corrosion causes "lattice growth" over time, i.e. the deformation of the positive lattice plates.

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Grid plates are designed as positive electrodes as well as negative electrodes. In addition to discharging the electric current, the grid structure also serves to hold the respective active masses, which are introduced by mechanical pasting. The low internal resistance of this design makes it a preferred solution in high-current applications (e.g. UPS). Nowadays, all negative plates in lead-acid accumulators are designed as grid plates.

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A high-current battery is capable of delivering a lot of power very quickly - but not for a long time. Such batteries are mainly used in the UPS sector, where they have to ensure the power supply for consumers for a few minutes in the event of a power grid failure. The high-current capability results from a low internal resistance in the structure of the battery, which allows the electrons to flow faster.

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HPPL batteries (High Performance Pure Lead) belong to the family of AGM batteries and therefore follow the basic structure - with the difference that the electrode thicknesses used correspond to only a fraction (approx. 25 %) of classic products. The potential of this technology lies in maximising the number of electrodes used. This results in a larger electrochemical reaction surface and is trend-setting in terms of energy and power density for lead-acid storage technologies. This is achieved by using pure lead for the production of the electrodes. Its superior corrosion properties compared to other lead alloys enable a significant reduction in the thickness of the electrodes while at the same time increasing their service life.

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This category includes vehicles used in intralogistics to transport, store and retrieve goods. This includes freely movable or track-guided vehicles such as forklifts, lift trucks, hoists and automated guided vehicles.

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The internal resistance of a cell is made up of various partial resistances. In addition to the metallic arresters, the electrolyte, the separators and the active masses also have a significant influence. The lower the internal resistance in a battery, the more current it can deliver per unit of time.

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Ions are electrically charged particles. Just like electrons, they can be carriers of electric current. Positively charged ions are called cations and negatively charged ions are called anions.

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Labyrinth plugs prevent gases from escaping from the cell via one or more openings in lead-acid batteries and retain electrolyte vapours (aerosols) via a labyrinth system. Through subsequent droplet formation, these aerosols then flow back into the cell.

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Large surface plates are always used as a positive electrode. It is a cast plate consisting of many small lead lamellae, similar in structure to a radiator in a motor vehicle. Compared to the grid plate, it has a reaction surface that is enlarged by a factor of 4 and is usually used where high-current batteries are required. However, the high material input and the associated costs are the downside of the oldest type of electrode.

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Accumulators of lead-acid technology contain positive and negative electrodes, which are mostly made of lead. The electrolyte that ensures the exchange of electrons between the plates consists of diluted sulphuric acid.

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According to the German Battery Association (ZVEI), the design life is a "value derived from the durability tests" - i.e. the theoretically expected life. The counterpart to this is the service life.

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In this type of battery, the negative electrode consists of e.g. graphite and the positive electrode of lithium metal oxygen. Lithium-ion batteries have a high energy density. They are therefore used especially where a lot of energy and the lightest possible battery are required.

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Maintenance-free batteries do not exist. The term is used in connection with the almost non-existent water consumption in sealed batteries: water refilling is not necessary. Nevertheless, general maintenance remains necessary even in sealed batteries and should take place at regular intervals (HOPPECKE recommendation: 1 time / year).

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Components that reduce water consumption or the use of an AquaGen (recombinator plug) can significantly reduce the maintenance of a battery. However, general maintenance remains necessary and should take place at regular intervals (HOPPECKE recommendation: 1 time / year).

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The monitoring of batteries enables, for example, the compact reading of the most important key figures of the battery in a charging station. In combination with a battery management system, the user always has an overview of the real-time data of his batteries and can plan their use accordingly so that, for example, electricity costs and energy consumption are reduced and faults are detected in time.

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Rated capacity Kn: Amount of electricity allocated to a battery during discharge under specified conditions. Nominal voltage Un: e.g. average voltage that occurs during discharge. Often used to roughly determine the number of cells in a battery. Nominal discharge time tN: fixed discharge time associated with the nominal capacity. Rated current In: calculated current associated with the rated capacity and discharge time. The battery can be loaded with this current for e.g. 10h at 20°C without falling below the respectively assigned final discharge voltage. Nominal temperature Tn: fixed electrolyte temperature assigned to the nominal capacity. Nominal density of the electrolyte (nominal acid density ρn): fixed value at nominal temperature, charged battery and fixed electrolyte level.

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The terms describe the way in which a system is supplied with electricity: On-grid applications are connected to the public grid, off-grid applications draw their energy from e.g. solar or wind power.

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The open-circuit voltage is the voltage at the cell when no electrical energy is flowing, i.e. when the battery is not in use. It should not fall below a certain value in order not to damage the battery.

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OPzS refers to closed batteries that are equipped with armour plates. The acid in the battery is in a liquid state. OPzS = stationary armour plate in acid

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OPzV batteries are also based on armour plates, but here the electrolyte is fixed with the help of a special gel. The batteries are sealed and therefore almost maintenance-free. OPzV = Fixed armour plate, valve-regulated.

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Charging beyond full charge is called overcharging and can lead to battery damage (electrolyte loss).

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State when the depth of discharge of the battery is in a range of 15 % DoD (Depth of Discharge) maximum (i.e. still 85 % charged)

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Peak shaving - also called load capping - is used to reduce electricity consumption during demand peaks. This can be done by using stored energy, for example from batteries, or by generating one's own electricity.

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A plate set refers to the alternating arrangement of positive and negative electrodes in a battery. To avoid a short circuit, they are separated from each other by a separator.

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Power density is the value that shows how much power (in watts) per mass or volume (in kg or ltr.) a battery can deliver.

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Power rails are components of charging stations - especially in logistics centres. They make it possible to supply all charging stations centrally with electricity without having to install individual cables for each charging station. Even if the charging station needs to be extended, the busbar can simply be extended.

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A primary element is an electrical storage device that is consumed when it is discharged, i.e. it cannot be recharged.

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In pure lead batteries, lead with a purity of 99.99% is usually used for the production of the electrodes. This makes the battery more resistant to corrosion.

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When operating accumulators with liquid electrolyte, not only is electrical energy stored during charging, but water is also decomposed, producing gases. These gases can escape, causing the electrolyte level to drop over time and the electrolyte concentration in the remaining water to increase. A recombination system ensures that the gases do not escape, but turn back into water and thus the electrolyte concentration remains the same.
AquaGen (recombinator plug)

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With the user-friendly roller-mounted battery change, the battery is loaded from the industrial truck onto a change trolley with a roller bed. With this, the battery can be moved to the free loading area and then pushed back onto a frame with a roller bed.
See also: trak | Xchange TU | trak | Xchange TU | trak | Xchange MU | trak | Xchange BT

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A secondary element is a storage device for electrical energy that, unlike a primary element, can be recharged after a discharge.

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The trigger for the self-discharge of storage systems with aqueous electrolyte is water decomposition, which starts above a voltage of 1.23 V (water decomposition voltage). For this reason, discharge takes place in a battery even if no device is connected - approx. 3 % per month is a guide value for closed batteries.

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The service life refers to the period of time during which the limit values of certain battery parameters are maintained in compliance with the maintenance regulations. The specified limit value for lead-acid batteries, for example, is 80 % of the nominal capacity - when this value is reached, the battery has reached the end of its service life. The service life is determined on the basis of field experience.

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Short circuit, external: Low-resistance electrical contact between the battery poles. Can lead to the destruction of the battery due to strong temperature development on the components. Short-circuit, internal: The cells can receive an internal short-circuit due to fine shorts (dendrite formation and sludge). This generally leads to an increased self-discharge and is noticed by a sharp drop in capacity.

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The short-circuit current Ik designates the maximum possible current of a battery that flows during a short-circuit.

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Charging stations must be as space-saving as possible, especially in the intralogistics area. System racks allow the chargers to be placed on pedestals - and the batteries directly underneath. A roller bed on which the batteries are placed additionally simplifies the battery change that is due when the battery is charged and can be used in an industrial truck.
See also: trak | Xcharge CS | trak | Xchange BS

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These include, for example, distribution stations, mobile phone repeaters and other devices that enable nationwide communication.
See also: application telecommunication

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Trickle charging is a charging method in which the battery is charged when fully charged and is therefore always ready for use. Trickle charging is used wherever the battery is used to power critical infrastructure (e.g. Uninterruptible Power Supply (UPS)).

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When the positive plate is inserted into a battery as a tubular plate, the active mass is thereby pressed into a kind of pocket (in tubular form) and thus armoured. This makes the battery corrosion and cycle resistant and gives it mechanical stability.

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This abbreviation stands for uninterruptible power supply. Behind it are batteries that temporarily take over the power supply in the event of a power failure of conventional grids. This protects critical infrastructure as well as data stored in data centres, medical equipment in hospitals, etc.

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When charging a battery, the chemical reactions inside cause the water contained in the battery to decompose into its components and gases to escape - thus increasing the acid density over time. To prevent corrosion and to keep the battery operational, water must therefore be added at regular intervals.

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The wet battery owes its name to the liquid acid-water mixture in which the positive and negative plate sets or the separator are located.

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