Calculation of inverter battery life. calculating battery life (battery) How to calculate how many hours a battery will last

In the life of modern man are used everywhere.

Almost any electrical equipment and electrical engineering is powered by power coming from chemical current sources.

Exhausted batteries are simply replaced with new ones, which determines the ease of use.

At the same time, few people know that still quite suitable batteries are often thrown into the trash, which must be restored using:

• a sharp nail or awl;
• syringe;
• battery charger;
• hot water;
• distilled water;
• table vinegar (9% concentration);
• hydrochloric acid solution (concentration 10%);
• small hammer;
• resin and plasticine.

So, within the framework of this article, we are increasing the operating time (service life) of a battery, which, it would seem, has already exhausted its working resource.

But first things first.

Extending battery life

Regeneration (restoration) of the power supply is possible only if its capacitance and voltage have not dropped to the limit value.

AA batteries (1.5 Volts) withstand a minimum threshold of 0.7-0.8 Volts. If this value has not yet been reached, you can start resuscitation.

The easiest way to increase the life of batteries that are discharged under high load. Such batteries can be found in flashlights, toys, radios, etc.

Chemical current sources that are discharged under low loads (clocks, radio, photographic equipment) recover much worse, because. evenly develop the required resource without a trace.

A battery that has been lying idle for a long time and dried up can be regenerated by the following operations:

1. We make double-sided holes to a depth of 3/4 with a thin metal object (nail or awl) along the length of the battery from both of its edges, along the rod.

2. We inject a little purified or distilled water (with a syringe) into the hole made.

3. We observe how water passes inside the battery and displaces air from another hole.

4. As soon as water passes through all the batteries, it begins to protrude on the opposite side, we close the holes with resin or plasticine.

5. Let's test the "recharged" battery in operation.

Battery life can be increased by injecting not water, but table vinegar (double dose) or hydrochloric acid solution.

If the steps above are too complicated, you can simply place the used battery in hot water for 10 minutes.

In addition, the battery life is increased as a result of mechanical stress.

For these purposes, we will need a small hammer, which needs to be tapped on the battery case.

Instead of a hammer, you can use any other object that does not damage the integrity of the body. 2-3 days of operation at low discharge currents are guaranteed!

In addition, you can try to revive the battery by placing it in a special charger. You can do this with extreme caution!

Simple disposable batteries are not designed to be recharged, therefore, such actions can be used at your own risk and fear !!!

Equipment in watts. We need to find out exactly the average (over the time from ) consumption. It may differ from the maximum or rated power indicated in the descriptions of the equipment.

For example, the rated power of a computer power supply can be 500 W, and the actual power consumption is 120 W (low power processor - 60 W, not too sophisticated motherboard with an integrated video adapter - 50 W and a small hard drive - 10 W).

In the second example. The refrigerator connected to the refrigerator has a compressor with an electric power of 200 W, but this compressor turns on once every 10 minutes and runs for 2 minutes. In this case, the average consumption will be equal to:

200 W / 10 min. * 2 minutes. = 40 W

If the refrigerator has annual energy consumption in kilowatt-hours (for example, 270 kWh per year), then to calculate the average power, this value must be divided by 9:

P = 270 / 9 = 30 W

We are interested in the average active power equipment powered by, i.e. power expressed in watts (W), not volt-amperes (VA). If only the apparent power (in VA) is known, then it must be multiplied by a factor from 0.6 to 1.0, depending on the characteristics of the equipment.

2. Calculation of the total

For example, it has a built-in, consisting of 2

For simplicity, we have made calculation calculators:

And now we present the calculation algorithm:

1) Determine the total load power and constant discharge current.

2) We calculate the required battery capacity for a given autonomy.

3) Determine the type of battery

Example

Given: two LED strips with a power of 10W and operating from 12V. Required autonomy: 10h. Service life: one year with daily use. Operating conditions: constant room temperature 20 degrees.

Find: minimum allowable and optimal accumulators for solving the problem.

Solution

1) Total power W=10W*2=20W. Constant discharge current: I=20/12=1.67A. For accurate calculations, it is desirable to measure the current consumption using a multimeter.

2) To determine the required capacity, go through the points:

a) In order to keep the load at such a discharge current, it is necessary to determine the minimum calculated battery capacity: 1.67 * 10 = 16.7Ah.

b) It must be borne in mind that the capacity of batteries is indicated by manufacturers based on a certain discharge time. Usually it is 10 hours. But some manufacturers indicate 20 hours. Here we will be helped by the battery, which can be taken on our website. Let's see the specification:

In our case, the battery life is 10 hours, which means we can consider the capacity equal to the nominal one. However, if the task costs 5 hours, then you need to make an allowance for the fact that with such a discharge time, the battery capacity will be lower (we multiply the discharge current by hours - 4.8A * 5h = 24Ah instead of 28).

In the task, we can see that the planned number of cycles we have is 365. The estimated maximum discharge depth in our case is about 57%. It is advisable to take it with a margin, we will count on a 50% discharge (actual operating conditions are different from ideal laboratory conditions).

Thus, we introduce an amendment of 0.5: 16.7 / 0.8 \u003d 33.4Ah.

G) In case we are dealing with an operating temperature different from the optimal one (25 degrees), it is necessary to enter a correction factor, which we can also take from the specification:

So at a temperature of 10 degrees, a coefficient of 0.9 should be entered, i.e. +10% more to the calculated capacity.

3) If we need long discharge modes, we should pay attention to the AGM series of batteries from manufacturers popular on the Russian market:

• Battery Delta - series
• At CSB -

Many devices that surround us in everyday life require regular battery replacement. But some batteries last a long time, while others "die" almost immediately, especially in the cold. Why? We offer you to figure out what certain types of power sources are suitable for, whether they are wireless headphones, computer mice or TV remote controls, and how to save money when choosing them.

The Italian physicist Alessandro Volta became the author of the world's first battery. He discovered that chemical processes that occur between electrodes made of different metals can become a source of electric current. Volta designed an element in which plates of zinc and copper alternated, and pieces of cloth impregnated with hydrochloric acid were laid between them. The battery was placed in a conductive salt solution - electrolyte. A potential difference was created at the outputs, summing up the voltage of all elements connected in a column, as a result, an electric current arose.

Alessandro Volta presented his invention to the Royal Society of London in 1801, after which he was invited to Paris by Napoleon I Bonaparte, so that the physicist would personally demonstrate to him the operation of the battery. For this, Volta was awarded the Order of the Legion of Honor, the title of King of Electricians and a prize of 6 thousand lire.

The first mass production of batteries was established by the American company Eveready at the end of the 19th century. Then power supplies for radio receivers were produced, later they began to be used in the mining industry, in the automotive industry, in the navy and in aviation. In the 20s of the last century, the American battery market was captured by Duracell, and therefore for a long time manganese-zinc galvanic cells with a graphite electrode “dominated”.

Then came new technologies, and with them new manufacturers. Today, the most popular brands on the Russian market are GP, Energizer, Duracell, Varta, Cosmos. Current sources differ in power, which, in turn, depends on the filling. Depending on the composition - cathode, anode and electrolyte - batteries are hydrochloric, alkaline, mercury, lithium and silver.

Types by composition

Salt batteries came to replace manganese-zinc batteries in the second half of the 20th century. In saline, an ammonium chloride solution is used as an electrolyte, it contains electrodes made of zinc and manganese oxide. Salt batteries are the most inexpensive of all batteries on the market.

However, most manufacturers have already abandoned the production of these galvanic cells, and you can hardly find them on sale. Surely, many have noticed a white coating or accumulation of grains of salt in the battery compartment. It turned out that these current sources are more likely than others to depressurize, as a result, the electrolyte flows out, which affects the service life of the equipment. In addition, it is also dangerous for humans - if salt gets on the skin or mucous membranes, then there is a risk of getting burned.

Alkaline is also popularly known as alkaline (from the English alkaline - “alkali”). They are slightly more expensive than salt ones, however, their benefits are many times greater: with a continuous discharge, they are able to work much longer than salt ones, and with a more intense load. Batteries of this type cost an average of about 20 - 30 rubles per battery.

Mercury, like hydrochloric, is almost never found on sale, they are being discontinued due to the toxicity of mercury. They also require special disposal conditions. In addition, during cyclic operation, the galvanic cell quickly degrades and its capacity decreases.

Lithium batteries last the longest at high loads. In such a battery, the cathode is made of lithium, it is separated from the anode using a separator and a diaphragm, which is impregnated with an organic electrolyte. At the same time, lithium batteries are the lightest of all existing ones, but their only drawback in price is the cost of one package of two batteries, about 150 rubles.

Silver batteries are also among the most expensive, silver oxide serves as the basis for the cathode, and zinc for the anode. The electrolyte is sodium or potassium hydroxide. They have stable voltage and high capacitance. “By themselves, these batteries are good: they are stored for a long time and are slowly discharged. I installed it and forgot about changing the current elements for five years. But you rarely see them in stores because of the high price, ”explained Artyom Novikov, sales assistant at the Technocity store.

"Reusable"

Experienced users prefer to buy rechargeable batteries instead of disposable ones, as they can be recharged many times. Batteries can be distinguished by the inscription Rechargeable, as well as by the capacity indicated on the case in milliamp-hours (mAh). To recharge, you need a special device that plugs into an outlet, its cost varies from 300 to 4 thousand rubles.

On the shelves of stores you can often find nickel-cadmium and nickel-ion batteries. “Rechargeable batteries are a promising direction both in science and in production. Rechargeable power supplies are also environmentally friendly due to reusable use. So batteries will soon replace disposable batteries. Scientists are constantly working on developing new materials. For example, the Novosibirsk Research Institute of Solid State Chemistry is working on the synthesis of sodium-ion batteries, in the future, the development of magnesium-ion power sources,” said Nina Kosova, Candidate of Chemical Sciences.

Types by size

However, disposable batteries are too early to be thrown into the dustbin of history. First of all, affordability will not allow them to be scrapped, so it is useful to understand the classification of batteries by size.

AAA - a small battery, popularly known as a "little finger" battery. About 4.5 centimeters high and about a centimeter in diameter. The voltage is 1.5 volts.

AA - another miniature battery, it is also called "finger-type". The height is 5.5 centimeters, the diameter is about 1.5 centimeters, and the voltage is no more than 1.5 volts.

C - these batteries are called "inch" or "esk" because of the height - five centimeters. The diameter is 2.6 centimeters, and the voltage is 1.5 volts.

D is the largest battery, which is why it was unofficially nicknamed the "barrel". The voltage is standard, the height is 6.1 centimeters, the diameter is 3.4 centimeters.

PP3, or "crown", is the element with the highest voltage of nine volts, 4.8 centimeters high and 2.6 centimeters in diameter. This battery has both contacts on the same side.

Application area

Salt batteries have a low capacity - about 0.8 amperes per hour. They are suitable for devices with low power consumption: remote controls, thermometers, wall clocks, kitchen or floor scales. These batteries lose their charge very quickly at low temperatures.

For alkaline, the scope is much wider, and they are designed for high loads. The capacity of such a battery is 1.5 - 3.2 amperes per hour. Alkaline cells are applicable to digital flash cameras, flashlights, children's toys, office phones, computer mice and so on.

Lithium batteries have a longer lifespan, so these power supplies are used in devices that have a high power consumption. It can be computer and photographic equipment, medical equipment. In addition, such batteries are not afraid of frost. And they can be safely used for some street gadget.

Mercury batteries were widely used 20 years ago in devices such as electronic watches, pacemakers, hearing aids, and military devices. But today, as mentioned above, they were abandoned because of the high risk of getting poisoned.

Silver batteries were not widely used due to the high cost of the metal. However, miniature power supplies of this type are widely used in watches, laptop and computer motherboards, hearing aids, musical cards, key fobs. Krone-sized batteries are mainly inserted into radio-controlled toys or other devices that require high power.

When choosing a battery, you should also focus on the date of manufacture. “You always have to look at when the battery was made. If it has lain on a shelf in a store for a year, then you can be sure that it has lost its capacity by 10-20%. Therefore, never buy batteries for future use. Salt has the shortest shelf life - about two years; up to five years, alkaline can be stored, and up to seven - lithium," said sales assistant Artyom Novikov.

How to choose the optimal UPS configuration for uninterruptible power supply of equipment and household appliances in the house

It is quite difficult to answer the question about choosing the configuration of an uninterruptible power supply to ensure reliable power supply for heating and engineering systems, household electrical appliances. In fact, this is an equation with many unknowns. After all, it is not known in advance how bad the network power supply will be, and how long the power outages will be.

At the first stage, it is necessary to determine the total capacity of all energy consumers, the operation of which must be ensured in the event of a mains power failure. Based on this value, it is necessary to select a UPS with a capacity of 20% higher than the maximum load value. After that, you need to determine the capacity of external batteries, based on the required backup time.

The most optimal solution for uninterruptible power supply would be to break the load into several smaller groups of consumers. And solve the problem of providing a reserve separately for different groups of consumers, depending on their importance. When choosing an uninterruptible power supply and battery configuration, it should be taken into account that increasing the UPS power reserve does not lead to a linear increase in the duration of the reserve. To provide a large load power, a more powerful UPS is needed, and to provide a large standby time, it is necessary to increase the capacity of external batteries.

An easy way to calculate uninterruptible backup time

The power reserve time is determined primarily by two parameters: the power of the payload and the total capacity of all batteries.

However, it should be noted that the dependence of the reserve time on these parameters is not linear. However, a simple formula can be used to quickly estimate the reserve time.

T=E*U/P(hours),

whereE - capacitybatteries,U - voltagebatteries,P - load powerall connected devices.

An improved method for calculating the uninterruptible backup time

To clarify the calculation of the reserve time, special coefficients are additionally introduced: inverter efficiency, battery discharge coefficient, available capacity coefficient depending on the ambient temperature.

Taking into account these coefficients, the calculation formula takes the following form.

T=E*U/P*KPD * KRA * KDE(hours),

where KPD (inverter efficiency) is in the range of 0.7-0.8,

KRA (battery discharge rate) is in the range of 0.7-0.9,

KDE (Capacity Available Ratio) is in the range of 0.7-1.0.

The available capacitance factor has a complex dependence on the temperature value and the rate of application of the load. The colder the air temperature, the lower the available capacity factor. The slower the battery power is consumed, the greater the value of the available capacity factor.

Ready-made tables of reserve time values ​​of SKAT and TEPLOCOM series uninterruptible power supplies

Requires one external 12 volt battery

Estimated reserve time table

Requires two external 12V batteries

Estimated reserve time table

Requires 8 external batteries with a voltage of 12 volts

Line of UPS brands SKAT and TEPLOCOM provides the possibility of organizing a reliable uninterruptible power supply for consumers of various capacities and purposes. Uninterruptible power supplies make it possible to organize uninterrupted power from a small heating boiler or circulation pump to powering the entire house or office. Specialized UPSs enable the organization of uninterruptible power supply for critical facilities, such as communication systems, communication equipment, security and control systems.

There are several ways to increase the payload backup time. All these methods follow from the formula for calculating the reserve time.

To increase the backup time, you can increase the capacity of external batteries, reduce the payload, create optimal operating conditions for the UPS and batteries.

First option- the simplest, but costly. To increase the capacity of the batteries, you will have to buy more expensive batteries and UPSs that allow them to be efficiently charged. In addition to the cost of equipment, it will also be necessary to allocate a special room for the storage and operation of batteries, equipped with a good ventilation system.

Second method- reduce the load. First of all, you need to divide the load into groups depending on the need to ensure uninterrupted power supply. If there is no electricity for a long time, then it will be necessary to choose between the importance of ensuring the operation of engineering heating systems, water supply and the need to use a refrigerator or air conditioner. So a modern refrigerator allows you to provide an acceptable temperature for about 20 hours, if you do not open it once again. Another group of consumers is the lighting system; autonomous uninterruptible power supplies or emergency lights with a built-in battery can be used for lighting. Ultimately, you can sit by the light of a flashlight or a good old candle, everything is better than defrosting the heating system.

Third method is to improve the quality of service for the UPS and batteries. Here the most important points are keeping the equipment clean, ensuring a good temperature regime. Separately, it is worth noting the need for proper battery charging and battery training. It often happens that there are no problems with electricity, and batteries do not undergo discharge and charge cycles. As a result, after a few months, the actual capacity of the battery drops sharply. To train the battery, you must use special equipment or simulate periodic power outages, allowing the batteries to work.