The voltage of the battery, along with the capacity and density of the electrolyte, makes it possible to conclude about the state of the battery. By voltage car battery you can judge the degree of its charge. If you want to be aware of the condition of your battery and take proper care of it, then you definitely need to learn how to control the voltage. Moreover, it is not difficult at all. And we will try to explain in an accessible way how this is done and what tools are needed.
First, you need to determine the concepts of voltage and electromotive force (EMF) of a car battery. EMF ensures the flow of current through the circuit and provides a potential difference at the terminals of the power supply. In our case, this is a car battery. The battery voltage is determined by the potential difference.
EMF is a value that is equal to the work expended to move the positive charge between the terminals of the power supply. The values of voltage and electromotive forces are inextricably linked. If no electromotive force occurs in the battery, then there will be no voltage at its terminals. It should also be said that voltage and EMF exist without the passage of current in the circuit. In the open state, there is no current in the circuit, but the electromotive force is still excited in the battery and there is voltage at the terminals.
Both values, EMF and vehicle battery voltage are measured in volts. It is also worth adding that the electromotive force in a car battery arises from the flow of electrochemical reactions inside it. The dependence of the EMF and battery voltage can be expressed by the following formula:
E = U + I * R 0 where
E - electromotive force;
U is the voltage at the battery terminals;
I is the current in the circuit;
R 0 - internal resistance of the battery.
As can be understood from this formula, the EMF is greater than the battery voltage by the amount of voltage drop inside it. In order not to clog your head with unnecessary information, let's say it easier. Battery electromotive force is the voltage across the battery terminals, excluding leakage current and external load. That is, if you remove the battery from the car and measure the voltage, then in such an open circuit it will be equal to the EMF.
Voltage measurements are made with instruments such as a voltmeter or multimeter. In the battery, the EMF value depends on the density and temperature of the electrolyte. With an increase in the density of the electrolyte, the voltage and EMF increase. For example, with an electrolyte density of 1.27 g / cm 3 and a temperature of 18 C, the voltage of the battery bank is 2.12 volts. And for a storage battery consisting of six cells, the voltage value will be 12.7 volts. This is the normal voltage of a car battery that is charged and not under load.
Normal vehicle battery voltage
The car battery should be between 12.6-12.9 volts if fully charged. Measuring the battery voltage allows you to quickly assess the state of charge. But the real condition and deterioration of the battery cannot be recognized by voltage. To get reliable data on the state of the battery, you need to check its real and carry out a load test, which will be discussed below. We advise you to read the material on how.
However, with the help of the voltage, you can always find out the state of charge of the battery. Below is a table of the state of charge of the battery, which gives the values of voltage, density and freezing point of the electrolyte depending on the battery charge.
| Battery charge level,% | ||||
|---|---|---|---|---|
| Electrolyte density, g / cm cub. (+15 degrees Celsius) | Voltage, V (without load) | Voltage, V (with a load of 100 A) | Battery charge level,% | Freezing point of electrolyte, gr. Celsius |
| 1,11 | 11,7 | 8,4 | 0 | -7 |
| 1,12 | 11,76 | 8,54 | 6 | -8 |
| 1,13 | 11,82 | 8,68 | 12,56 | -9 |
| 1,14 | 11,88 | 8,84 | 19 | -11 |
| 1,15 | 11,94 | 9 | 25 | -13 |
| 1,16 | 12 | 9,14 | 31 | -14 |
| 1,17 | 12,06 | 9,3 | 37,5 | -16 |
| 1,18 | 12,12 | 9,46 | 44 | -18 |
| 1,19 | 12,18 | 9,6 | 50 | -24 |
| 1,2 | 12,24 | 9,74 | 56 | -27 |
| 1,21 | 12,3 | 9,9 | 62,5 | -32 |
| 1,22 | 12,36 | 10,06 | 69 | -37 |
| 1,23 | 12,42 | 10,2 | 75 | -42 |
| 1,24 | 12,48 | 10,34 | 81 | -46 |
| 1,25 | 12,54 | 10,5 | 87,5 | -50 |
| 1,26 | 12,6 | 10,66 | 94 | -55 |
| 1,27 | 12,66 | 10,8 | 100 | -60 |
We advise you to periodically check the voltage and charge the battery as needed. If the voltage of the car battery falls below 12 volts, it must be recharged from the mains charger... Its operation in this state is highly discouraged.
Operating the battery in a discharged state leads to an increase in the sulfation of the plates and, as a consequence, a drop in capacity. In addition, it can lead to a deep discharge, which is similar to death for calcium batteries. For them, 2-3 deep discharges are a direct route to the landfill.
Well, now about what tool a car enthusiast needs to monitor the voltage and state of the battery.
Car Battery Voltage Monitoring Tools
Now that you know what the normal voltage of a car battery is, let's talk about measuring it. To monitor the voltage, you need a multimeter (also called a tester) or an ordinary voltmeter.
To measure the voltage with a multimeter, you need to put it in the voltage measurement mode, and then attach the probes to the battery terminals. The battery must be removed from the car or the terminals must be removed from it. That is, measurements are taken on an open circuit. The red probe goes to the positive terminal, the black one goes to the negative terminal. The display will show the voltage value. If you mix up the probes, nothing bad will happen. Just a multimeter will show a negative voltage value. Read more about it in the article at the specified link.
There is also such a device as a load plug. They can also measure voltage. For this, the load plug has a built-in voltmeter. But much more interesting for us is that the load plug allows you to measure the battery voltage in a closed circuit with resistance. From these readings, you can judge the state of the battery. In fact, the load fork simulates the start of a car engine.
To measure the voltage under load, connect the terminals of the load plug to the battery terminals and turn on the load for 5 seconds. At the fifth second, see the readings of the built-in voltmeter. If the voltage has dropped below 9 volts, then the battery has already lost its performance and should be replaced. Of course, provided the battery is fully charged and in an open circuit it produces a voltage of 12.6-12.9 volts. On a working battery, when the load is applied, the voltage will first drop somewhere up to 10-10.5 volts, and then it will begin to grow slightly.
What do you need to remember?
In conclusion, here are some tips that will save you from mistakes when using the battery:
- measure the battery voltage periodically and recharge it regularly (once every 3 months) from the mains charger;
- keep the alternator, wiring and voltage regulator of the vehicle in good working order for normal battery charging when traveling. The leakage current value must be checked regularly. and its measurement is described in the article at the link;
- check the density of the electrolyte after charging and refer to the table above;
- keep the battery clean. This will reduce the leakage current.
Attention! Never short-circuit the terminals of a car battery. The consequences will be dire.
That's all I wanted to say about the voltage of the car battery. If you have additions, corrections and questions, write them in the comments. Successful operation of the battery!
Posted inIs it possible to accurately judge the state of charge of the battery by the EMF?
The electromotive force (EMF) of a battery is the difference between its electrode potentials, measured with an open external circuit:
Е = φ + - φ–
where φ + and φ– are the potentials of the positive and negative electrodes, respectively, when the external circuit is open.
EMF of a battery consisting of n series-connected batteries:
In turn, the electrode potential in an open circuit in the general case consists of the equilibrium electrode potential, which characterizes the equilibrium (stationary) state of the electrode (in the absence of transient processes in the electrochemical system), and the polarization potential.
This potential is generally defined as the difference between the potential of an electrode during discharge or charge and its potential in an equilibrium state in the absence of current. However, it should be noted that the state of the battery immediately after turning off the charging or discharge current is not equilibrium due to the difference in the concentration of the electrolyte in the pores of the electrodes and the interelectrode space. Therefore, electrode polarization remains in the battery for a rather long time even after disconnecting the charging or discharge current and characterizes in this case the deviation of the electrode potential from the equilibrium value due to the transient process, that is, mainly due to diffusion equalization of the electrolyte concentration in the battery from the moment the external circuit is opened to the establishment of equilibrium stationary state in the battery.
The chemical activity of the reagents collected in the electrochemical system of the battery, and, therefore, the change in the EMF of the battery depends very little on temperature. When the temperature changes from –30 ° С to + 50 ° С (in the operating range for the battery), the electromotive force of each battery in the battery changes by only 0.04 V and it can be neglected during battery operation.
With an increase in the density of the electrolyte, the EMF increases. At a temperature of + 18 ° C and a density of 1.28 g / cm3, the battery (meaning one bank) has an EMF equal to 2.12 V. A battery of six cells has an EMF equal to 12.72 V (6 × 2.12 V = 12 , 72 V).
The EMF cannot be used to accurately judge the state of charge of the battery.
The EMF of a discharged battery with a higher electrolyte density will be higher than the EMF of a charged battery, but with a lower electrolyte density. The EMF value of a working battery depends on the density of the electrolyte (the degree of its charge) and varies from 1.92 to 2.15 V.
During operation rechargeable batteries the way EMF measurements you can detect a serious malfunction of the battery (shorting of plates in one or several banks, breakage of connecting conductors between banks, and the like).
EMF is measured with a high-resistance voltmeter (the internal resistance of the voltmeter is less than 300 Ohm / V). During measurements, a voltmeter is connected to the terminals of the battery or battery. In this case, no charging or discharging current must flow through the accumulator (battery)!
***
Electromotive force (EMF) is a scalar physical quantity that characterizes the work of external forces, that is, any forces of non-electrical origin acting in quasi-stationary DC or AC circuits.
EMF, like voltage, in the International System of Units (SI) is measured in volts.
The rechargeable battery is one of the most complex devices modern car... Many electrochemical and physical processes, interrelated and largely due to the influence of external factors, continuously proceed in it. And like any complex device, it requires appropriate care with the appropriate qualifications.
The car enthusiast, for the most part, is interested in purely practical issues. Such as, for example, why does the battery not provide the start of a perfectly serviceable engine after two seasons? Why did the battery last only two years, and not 5 or 8 years, although the car passed 3 thousand km a year due to the lack of gasoline? What should be done to ensure that the battery lasts a long time and does not fail at the most inopportune moment? And how much time to devote to her, and shouldn't she be fiddling with her every day? And many other similar questions.
To answer these questions, you must use not only ready-made recommendations and instructions, but also have a certain level of knowledge about batteries.
Batteries, like other chemical power sources, are being intensively studied and improved, but often many publications are not available to the motorist and understanding a number of issues requires special professional training. In many magazine articles, tutorials, recommendations, instructions, etc. along with the absolutely correct and useful information there is a lot of subjectivity, and in a number of cases, unfortunately, there is a lack of understanding, ignorance and corporate interests of the authors (especially in the magazine "Za Rulem").
This manual has a very simple purpose - to give the car enthusiast an initial knowledge of caring for a battery. We tried to avoid complicated theoretical calculations and formulas. Nevertheless, theoretical information cannot be completely ruled out.
Without understanding the main processes taking place in a battery under certain conditions, it is impossible to build an optimal tactics for caring for a battery in real operating conditions.
(the battery itself), to avoid annoying mistakes, even using a huge number of correct recommendations.
We understand that this manual is also not without its shortcomings, however, we tried to set out in a logical sequence the known facts, various methods and work performed on caring for
battery. We hope that the material presented in the manual will help the car enthusiast in caring for the battery.
2. BASIC PROCESSES IN THE BATTERY
2.1. Concepts and definitions
The battery is a reversible current source. It is able to transfer previously stored energy to the load in the external circuit. On cars batteries are installed, consisting of six batteries connected in series. They are capable of providing high discharge currents and belong to the class of starter batteries. This is reflected in the labeling of the batteries. For example, a 6ST-55 battery contains 6 batteries, a starter one, with a nominal energy capacity of 55 ampere-hours.
Here are some basic concepts and definitions that characterize a storage battery in various operating modes.
Electromotive force (EMF) is the difference in electrode potentials when the electrical circuit is open. The EMF of the battery depends on the density of the electrolyte temperature and the composition of the active mass of the plates. The EMF is expressed in volts and is usually denoted by the letter E ... You can measure the EMF with a voltmeter with a large internal resistance exceeding 20 kOhm.
EMF at rest (E0) is the EMF of a battery that is unloaded for a long time (more than 2-3 hours).
The EMF of the battery under load differs from the EMF of rest. This is due to the fact that during the passage of current in the circuit, irreversible physical and chemical processes associated with the loss of energy occur on the electrodes and in the electrolyte. One of them is the polarization process.
EMF polarization ( Ep ) is the EMF of the battery in the presence of polarization of the plates.
En is always directed towards the current.
When charging, the EMF of the battery is equal to the sum of the EMF of rest and the EMF of polarization:
E = E0 + En ,
while charging
E = E0 - En .
The value E called the dynamic EMF, or simply the EMF of the battery.
In a closed electrical circuit direct current when consumers are connected to the battery, the connection between the EMF, the current passing through the circuit and the resistance of the circuit is determined according to Ohm's law:
E = I (R + r), (1)
where E - EMF, V;
I - current in the circuit, A;
R - active resistance of the external circuit, Ohm;
r is the total resistance of the section of the electrical circuit inside the current source itself, Ohm.
Expression (1) can be rewritten as:
E = IR + Ir , (2)
those. The battery emf compensates for the voltage drop on the external circuit U = IR and the voltage drop inside the current source itself at its total internal resistance Ur = I * r .
The magnitude U = I * R is the battery voltage. This is the voltage at the terminals of the battery, which is used to operate the current consumers.
From equation (2) it can be seen that when the battery is operating, its voltage is U always less than EMF, since
U = E - Ur .
As the battery wears out, its internal resistance increases. This is one of the reasons for the undervoltage at the battery terminals under load. as Ur increases. The situation is similar for a discharged battery.
Distinguish between charging voltage equal to
Ue = E + Iz * r ,
and discharge voltage:
Uр - E - Iр * r ,
where Iз - charging current, A;
Ip - discharge current, A;
r is the internal resistance of the battery, Ohm.
Normal charging current - charging current value ( A ).
numerically equal to 0.1 of the battery capacity, expressed in ampere-hours.
The internal resistance of the battery is the sum of the resistance of the electrodes, the electrolyte, and the resistance caused by the separators (spacers between the plates). Internal resistance is a variable quantity. It depends on the design of the electrodes, the state of the active mass, the density of the electrolyte, and temperature. A fully charged battery has significantly less internal resistance than a discharged battery. This is explained by the fact that the electrical conductivity of the active mass of a charged battery is higher than that of a discharged one.
Battery capacity is the amount of electricity that the battery can store or deliver.
The capacity depends on the magnitude of the discharge current. The battery capacity is defined as a value equal to the product of direct current and time in a 20-hour discharge mode to a voltage of 1.7 V:
Q20 = Ip * tp = Ip * 20 (A * h),
where Ip - the value of the discharge current,
tр - discharge time.
Discharge current capacity Qр - nominal capacity of the battery at discharge:
Qp = Ip * tp ,
where Ip - value of the discharge current, A;
tp - discharge time.
Battery charging capacity - characterizes the amount of electricity received by the battery during charging:
Qz = Iz * tz ,
where Qz - charging capacity, A * h;
Iз - charging current, A;
tz - charging time, h
Modern batteries have a capacity efficiency of 0.85.
Energy capacity - characterizes the ability of the battery to perform electrical work in a certain amount of time.
Measured in watt-hours.
Energy capacity on discharge:
Ap = Up * Ip * tp ,
Electromotive force
The electromotive force (EMF) of the battery E is the difference between its electrode potentials, measured with an open external circuit.
EMF of a battery consisting of n series-connected batteries.
It is necessary to distinguish between the equilibrium EMF of the battery and the nonequilibrium EMF of the battery during the time from opening the circuit to the establishment of an equilibrium state (the period of the transient process). EMF is measured with a high-resistance voltmeter (internal resistance of at least 300 Ohm / V). To do this, a voltmeter is connected to the terminals of the battery or battery. In this case, no charging or discharging current should flow through the accumulator (battery).
The equilibrium EMF of a lead battery, like any chemical current source, depends on the chemical and physical properties of the substances participating in the current-forming process, and does not depend at all on the size and shape of the electrodes, as well as on the amount of active masses and electrolyte. At the same time, in a lead-acid battery, the electrolyte is directly involved in the current-forming process on the battery electrodes and changes its density depending on the state of charge of the batteries. Therefore, the equilibrium EMF, which in turn is a function of the density
The change in the EMF of the battery from temperature is very small and during operation it can be neglected.
Charge and discharge voltage
The potential difference at the pole terminals of the battery (battery) in the process of charging or discharging in the presence of current in the external circuit is usually called the voltage of the battery (battery). The presence of the internal resistance of the battery leads to the fact that its voltage during discharge is always less than the EMF, and during charging it is always higher than the EMF.
When charging the battery, the voltage at its terminals must be greater than its EMF by the amount of internal losses. At the beginning of the charge, there is a voltage jump by the amount of ohmic losses inside the battery, and then a sharp increase in voltage due to the polarization potential, caused mainly by a rapid increase in the density of the electrolyte in the pores of the active mass. Further, a slow increase in voltage occurs, mainly due to an increase in the EMF of the battery due to an increase in the density of the electrolyte.
After the main amount of lead sulphate is converted to PbO2 and Pb, the energy consumption increasingly causes the decomposition of water (electrolysis). The excess amount of hydrogen and oxygen ions appearing in the electrolyte further increases the potential difference between opposite electrodes. This leads to a rapid increase in the charging voltage, which accelerates the decomposition of water. The resulting hydrogen and oxygen ions do not interact with active materials. They recombine into neutral molecules and are released from the electrolyte in the form of gas bubbles (oxygen is released on the positive electrode, hydrogen is released on the negative one), causing the electrolyte to "boil".
If you continue the charging process, you can see that the increase in the density of the electrolyte and the charging voltage practically stops, since almost all the lead sulfate has already reacted, and all the energy supplied to the battery is now spent only on the side process - the electrolytic decomposition of water. This also explains the constancy of the charging voltage, which serves as one of the signs of the end of the charging process.
After stopping the charge, that is, disconnecting the external source, the voltage at the terminals of the battery drops sharply to the value of its nonequilibrium EMF, or by the value of ohmic internal losses. Then there is a gradual decrease in the EMF (due to a decrease in the density of the electrolyte in the pores of the active mass), which continues until the concentration of the electrolyte in the volume of the battery and the pores of the active mass is completely equalized, which corresponds to the establishment of an equilibrium EMF.
When the battery is discharged, the voltage at its terminals is less than the EMF by the amount of the internal voltage drop.
At the beginning of the discharge, the battery voltage drops sharply by the value of ohmic losses and polarization due to a decrease in the electrolyte concentration in the pores of the active mass, that is, concentration polarization. Further, with a steady (stationary) discharge process, the density of the electrolyte in the volume of the battery decreases, causing a gradual decrease in the discharge voltage. At the same time, there is a change in the ratio of the content of lead sulfate in the active mass, which also causes an increase in ohmic losses. In this case, the particles of lead sulfate (having about three times the volume in comparison with the particles of lead and its dioxide, from which they were formed) close the pores of the active mass, which prevents the passage of the electrolyte into the depth of the electrodes. This causes an increase in concentration polarization, leading to a more rapid decrease in the discharge voltage.
When the discharge is terminated, the voltage at the terminals of the battery rapidly increases by the amount of ohmic losses, reaching the value of the nonequilibrium EMF. A further change in the EMF due to the equalization of the electrolyte concentration in the pores of the active masses and in the volume of the battery leads to a gradual establishment of the value of the equilibrium EMF.
The battery voltage during its discharge is determined mainly by the temperature of the electrolyte and the strength of the discharge current. As mentioned above, the resistance of a lead-acid battery (battery) is negligible and in a charged state is only a few milliohms. However, at currents of the starter discharge, the strength of which is 4-7 times higher than the value of the nominal capacity, the internal voltage drop has a significant effect on the discharge voltage. An increase in ohmic losses with decreasing temperature is associated with an increase in the resistance of the electrolyte. In addition, the viscosity of the electrolyte sharply increases, which complicates the process of diffusion into the pores of the active mass and increases the concentration polarization (that is, increases the voltage loss inside the battery due to a decrease in the concentration of the electrolyte in the pores of the electrodes). At a current of more than 60 A, the dependence of the discharge voltage on the current strength is practically linear at all temperatures.
The average value of the battery voltage during charging and discharging is determined as the arithmetic mean of the voltage values measured at regular intervals.
Battery(element) - consists of positive and negative electrodes (lead plates) and separators separating these plates, installed in the body and immersed in an electrolyte (sulfuric acid solution). The accumulation of energy in the battery occurs during the course of a chemical oxidation reaction - reduction of electrodes.
Accumulator battery consists of 2 or more in series and / or parallel-connected sections (batteries, cells) to provide the required voltage and current.It is capable of accumulating, storing and giving off electricity, ensuring engine start-up, as well as powering electrical appliances when the engine is not running.
Lead Acid Battery- a storage battery, in which the electrodes are made mainly of lead, and the electrolyte is a sulfuric acid solution.
Active mass- this is a constituent part of the electrodes, which undergoes chemical changes when an electric current passes during charge-discharge.
Electrode- a conductive material capable of producing an electric current when it reacts with an electrolyte.
Positive electrode (anode) - an electrode (plate) whose active mass in a charged battery consists of lead dioxide (PbO2).
Negative electrode (cathode) - an electrode, the active mass of which in a charged battery consists of spongy lead.
Electrode grid serves to hold the active mass, as well as to supply and drain current to it.
Separator - material used to insulate electrodes from each other.
Pole leads serve to supply the charging current and to return it under the total voltage of the battery.
Lead -(Pb) is a chemical element of the fourth group of the periodic system of D. I. Mendeleev, serial number 82, atomic weight 207.21, valency 2 and 4. Lead is a bluish-gray metal, its specific gravity, in solid form, is 11.3 g / cm 3 decreases during melting depending on temperature. The most ductile among metals, it rolls well to the thinnest sheet and is easily forged. Lead is easily machined and belongs to low-melting metals.
Lead (IV) oxide(lead dioxide) PbO 2 is a dark brown heavy powder with a subtle characteristic smell of ozone.
Antimony is a metal of silvery-white color with a strong luster, crystalline structure. In contrast to lead, it is a hard metal, but very brittle and easily crushed into pieces. Antimony is much lighter than lead, its specific gravity is 6.7 g / cm 3. Water and weak acids do not affect antimony. It dissolves slowly in strong hydrochloric and sulfuric acids.
Cell plugs cover the cell openings in the battery cover.
Central ventilation cap serves to close the gas outlet in the battery cover.
Monoblock is a polypropylene battery case, divided by partitions into separate cells.
Distilled water topping up the battery to compensate for battery losses due to water decomposition or evaporation. Use only distilled water to top up batteries!
Electrolyte is a solution of sulfuric acid in distilled water, which fills the free volumes of the cells and penetrates into the pores of the active mass of electrodes and separators.
It is able to conduct an electric current between electrodes immersed in it. (For central Russia with a density of 1.27-1.28 g / cm3 at t = + 20 ° С).
Sedentary electrolyte: To reduce the risk of electrolyte spilled from the battery, agents are used to reduce its fluidity. Substances can be added to the electrolyte that make it gel. Another way to reduce the mobility of the electrolyte is the use of glass mats as separators.
Open battery
- an accumulator with a plug with a hole through which distilled water is added and gaseous products are removed. The opening can be provided with a ventilation system.
Sealed battery- an accumulator that is closed under normal conditions, but has a device that allows gas to escape when the internal pressure exceeds a set value. Usually, additional filling of electrolyte into such a battery is impossible.
Dry-charged battery- a storage battery stored without electrolyte, the plates (electrodes) of which are in a dry charged state.
Tubular (shell) plate- a positive plate (electrode), which consists of a set of porous tubes filled with active mass.
Safety valve- part of the vent plug, which allows gas to escape in the event of excessive internal pressure, but does not allow air to enter the accumulator.
Ampere hour (Ah) is a measure electrical energy, equal to the product of the current strength in amperes and the time in hours (capacity).
Battery voltage- the potential difference between the terminals of the battery during discharge.
Battery capacity- the amount of electrical energy given off by a fully charged battery when it is discharged before reaching the final voltage.
Internal resistance- resistance to current through the element, measured in ohms. It consists of the resistance of the electrolyte, separators and plates. The main component is the electrolyte resistance, which changes with temperature and sulfuric acid concentration.
Electrolyte density - e then the characteristic of a physical body, equal to the ratio of its mass to the occupied volume. It is measured, for example, in kg / l or g / cm3.
Battery life- the period of useful battery life under specified conditions.
Outgassing- gassing during electrolysis of the electrolyte.
Self-discharge- spontaneous loss of capacity by the battery at rest. The self-discharge rate depends on the material of the plates, chemical impurities in the electrolyte, its density, the purity of the battery and the duration of its operation.
Battery EMF(electromotive force) is the voltage across the pole terminals of a fully charged storage battery when the circuit is open, that is, when there are no charge or discharge currents at all.
Cycle- one sequence of charge and discharge of the cell.
The formation of gases on the electrodes of a lead-acid battery. It is especially abundant in the final phase of charging a lead-acid battery.
Gel batteries- these are sealed lead-acid batteries (not sealed, since a small release of gases does occur when the valves are opened), closed, completely maintenance-free (not refilled) with a gel-like acid electrolyte (Dryfit and Gelled Electrolite-Gel technologies).
AGM technology(Absorbed Glass Mat) - absorbent fiberglass pads.
Energy return- the ratio of the amount of energy given up when the battery is discharged to the amount of energy required to charge to its original state under certain conditions. Energy efficiency for acid batteries under normal operating conditions is 65%, and for alkaline batteries 55 - 60%.
Specific energy- the energy given off by the battery during discharge per unit of its volume V or mass m, i.e., W = W / V or W = W / m. The specific energy of acid batteries is 7-25, nickel-cadmium 11-27, nickel-iron 20-36, silver-zinc 120-130 W * h / kg.
Short circuit in batteries occurs when electrically connecting plates of different polarity.
