# Advice 1: How to calculate battery capacity

Capacity of the battery or the battery is called quantity of electricity (charge Q). Typically, capacity is measured in the following units: ampere-hours or milliampere-hour. Thus, the battery capacity of 1000 milliampere-hour can provide a current of 1000 milliamps for one hour or a current of 100 milliamps for 10 hours. Given the voltage U can be evaluated stored in the battery energy: E = Q * U.
You will need
• A device for measuring battery capacity
Instruction
1
Understand the principle of determining the capacity of the battery. To start, charge the battery, then discharge it by the current I, and then measure the time T for which he is discharged. The product of current and capacity of the battery; calculate it by the formula Q = I * T. the same way you can measure the battery capacity, but unlike it, the battery after full charge can re-charge.
2
To measure the capacity of the battery use, discharge the battery through a resistor R to a voltage of about 1 V. the discharge Current is measure by the formula I = U / R. To measure the discharge time, use a clock that can operate from voltage of 1.5-2.5 V. to protect the battery from full charge, use solid state relays, for example, PVN012, which will disable the battery if the voltage drops to the minimum (in our case to 1).
3
Fully discharge the battery and connect it to the circuit. Set the clock to zero, and switch scheme. Moreover, the relay closes the contacts, starts the discharge of the battery through a resistor, and the voltage will be filed on the clock. The voltage across the resistor and the battery will gradually decrease, and when it reaches 1 V, the relay opens the contacts. After the cessation of the discharge clock will stop.
4
Please note – capacity is only that the charged battery is higher, as over time part of the charge lost through self-discharge. To see the amount of self-discharge, measure capacity immediately after charging, and then measure a week (month). Allowable self-discharge batteries type NiMh – about 10% a week.
5
To reduce the contact resistance of the battery, upgrade the wiring. Some holders battery loss can cause a steel spring, which is recommended to shunt with copper wire.

# Advice 2: How to know the battery capacity

The capacity of the battery is the amount of energy in it (of charge Q, of electricity). Measured capacity of the battery or batteries in milliamperes per hour or amps per hour. So, for example, a battery having a capacity of 1000 milliamps/hour, can provide a current of 1000 milliamps for one hour or a current of 100 milliamps for 10 hours, etc. Knowing the voltage U can be easily calculated stored in the battery energy is sufficient to know the formula: E = Q*U.
You will need
• charger., stopwatch.
Instruction
1
Buy, hire or borrow a special device to measure capacitance of the battery. Take the battery and fully charge it, then discharge it using the current (I). Measure the time (T) during which it will discharge.
2
Calculate the product of current, which will be the capacity of the battery. To do this, take the amperage and time, and multiply (Q = I*T). I note that in the same way you can measure the capacity of any battery, and regular batteries. But it should be remembered that the simple battery charge again, unlike a battery, it will be impossible.
3
In order to know the capacity of the battery, you can use other methods. So to measure the capacity of the specified device, you can use a special scheme that allows you to discharge the battery through the resistor (R). Moreover, such a discharge is performed to a voltage of approximately 1W. Then measure the discharge current according to the formula: I = U/R.
4
To measure the discharge time, you can use an ordinary watch, capable of working at 1.5 watts. When you discharge the battery, remember that the device should not be discharged completely, and for this it is necessary to use special solid relay, for example, PVN012. This relay allows time to disconnect the battery at the moment when the voltage drops to a minimum level. Allowed the reduction to 1W, as already noted.
5
Connect the discharged battery to the circuit. Enable the profile and set the stopwatch include clock. When the discharge reaches 1 W, the relay will close and clock will stop.
6
To see how much charge it loses battery after about a week or two of use, when discharge, it is necessary to measure the capacity of the device after it is fully charged and make such measurements after another week or two.

# Advice 3: How to measure battery voltage

The status and charge level of your batteries can be determined by measuring the voltage at the battery terminal. This can often be the only way if you have a sealed battery, in which it is impossible to measure the density of the electrolyte.
You will need
• - voltmeter,
• - hydrometer.
Instruction
1
In order to measure the voltage at the battery, use a digital voltmeter, capable of making measurements accurate to tenths and hundredths of a volt.

Before the measurements, disconnect the battery from all consumers and charging devices, and wait at least two hours.

After all of the chemical processes in the banks suspended, proceed with the measurements.
2
Connect wire (usually black) of the device labeled "-" to the negative battery terminal, and red, marked " + " sign to positive. The contact must be tight, on the ends of the wire should be clips.
Take readings. The charge level of your battery determine the table given below.
You can measure the voltage on each battery Bank, and thus to detect the faulty.
3
The batteries with liquid electrolyte can determine the charge level and residual voltage according to the density of the electrolyte.

To do this, take the hydrometer. Open your tube of cans battery and take the device in electrolyte. Mark and record the readings of the density in each jar.
4
The following table shows the values of the density of the electrolyte corresponding to the residual voltage, for 12 and 24 volt batteries. Correlate the measured density of the electrolyte existing at the time of the measurement voltage. Output the average voltage.

Determine the charge level of your battery in percent.
Note
Be sure to use when working with electrolyte rubber gloves and wear safety glasses!
Remember that measurements should be carried out not earlier than two hours after disconnecting the battery.

# Advice 4: How to calculate battery charge time

Now many devices are equipped with batteries AA or AAA, this cameras, wireless mice and keyboards and many others. Very often the charger cannot show whether there is enough time to charge the battery, so you need to calculate the required charge time.
You will need
• - battery;
• charger.
Instruction
1
Determine the time of charge of the battery packing in the charger, which always indicates the time for charging batteries of different capacities. But this time it is almost always less than needed. You can also find the charging time for the battery pack. For example, if you have a battery AAA GP 1000, then it indicates the capacity of 970 mA/ hour, the amount of time to charge – sixteen hours at a current of 93 mA. But to find a charger that can provide such a current, almost impossible.
2
Take the charger, for example, GP Power Bank mini, it read that charging batteries type AAA it supplies a current of 80 mA. Next, click on the link http://horisty.narod.ru/zaryad_akkumulyatorov.htm. Enter in the first box 970, that is, the capacity of the battery.
3
In the second – 80, i.e., the value of the charging current and as a result you will get the time needed to charge the battery. In this example, 20 hours and 57 minutes. Although the packaging of the device says that the batteries GP 1000 should be charged for 15 hours. If you can fulfill their exercise during this time, they will be charged only on 2/3.
4
Calculate the duration of the charge independently. To do this, take the value of battery capacity in mA/h, for example, 3300. Then turn the charger will see the value of the output current, for example, 150 mA. Divide the capacitance value for a current to find out the charge time in hours. 3300/150 - the result is twenty-two hours.
5
Just keep in mind that this time can be as real only in the case where the charging current at constant. Usually a charger to change the current in the charge process, first, its value is minimal and gradually increases.

# Advice 5: What is the battery capacity

The validity of the battery in the mobile phone or battery in the car directly depends on such specifications as storage capacity. Under the capacity of the battery understand the amount of energy that the device can hold and pay for a certain unit of time. The higher the capacitance, the longer battery life.
Battery capacity is the most important feature that defines how long a battery could power a device. The saved amount of power the battery is called electrical capacitance.

## Indicators battery capacity

Battery capacity is measured in ampere hours. This means that the battery will give the specified capacity for a specified time, that is a formula it will look like the product of the current A (Ampere) time (hour). For example, a battery with a capacity of 50 Ah (Ampere hours) can provide the load of the device 1A (ampere) for 50 hours. At this point in time the market batteries can offer batteries with capacity 1 - 2000 Amp hours.

The battery voltage you can judge his capacity at a given time, as well as the extent of its charging. The higher the battery, the higher voltage, which produces at the terminals of the battery. To control charge using special charger with a multimeter and a hydrometer.

## Control battery

In order to avoid overcharging of the battery used charger with charge control. They are equipped with all phones, tablets, laptops and almost all car chargers. This device allows you to control the process of electrical capacity battery.

The controlled voltage on the battery terminals, for example, at 100% the battery voltage of 12 Volts at the moment charge the battery will show the voltage at 12.7 Volts. This will mean that the battery is fully charged and the charger will stop feeding him.

With the help of a multimeter (tester) which also control the battery voltage. With it, measure the voltage at the terminals of the battery at the time of charging.

With the help of a hydrometer of the device is controlled directly charging environment of the rechargeable battery. The hydrometer shows the features of the density of the electrolyte in the battery. The higher the density, the more energy it will take battery. For example, a battery with a voltage of 12 Volts at 100% charge has a density of the electrolyte in 1,265.

The electrolyte density can be checked in stationary batteries. When testing capacity is necessary to be careful that the electrolyte does not hit on your skin and clothes as it can cause chemical burns.

If your battery is frequently discharged, that is not holding the load, it is a sign that it should be replaced.

# Advice 6: How to determine battery capacity

The capacity of the battery is the amount of energy it contained. The unit of measure for this value – ampere per hour. Knowing the capacity of the battery, you'll know about how long he can last.
Instruction
1
Take a special device to determine the capacity of the battery. Then do the following. Charge the battery fully, then discharge it using the current. Be sure to note the time during which it will discharge the battery. Then make the calculation.
2
Multiply the amperage that you used to discharge the battery for the time it took to complete the devastation, to know the capacity of the battery. The product of these two quantities is the amount of energy that can contain a battery. This way you can determine the capacity of any battery, from the battery of the car, and ending with ordinary battery.
3
Try to use another method to determine the capacity of the battery. To do this you need a special scheme through which you will be able to discharge the battery through a resistor. Discharge occurs at a voltage not exceeding 1 volt. Then, using the formula I = U/R, calculate the amperage. To measure the discharge time, use a stopwatch or an ordinary clock.
4
Observe an important condition – the battery must not be discharged completely. To prevent this undesirable effect, use solid state relays. It will allow to disconnect the battery at precisely the moment when the voltage drops to the minimum mark. You can also learn the capacity of the battery without the use of special tools, and the work of any complicated manipulation. As a rule, all the necessary information about the device specified on the label of the manufacturer.
5
Inspect the surface of the battery. There should be a sticker containing the necessary information required for the operation of the device. If the sticker is worn or missing, you will have to return to the operations described above.

# Advice 7: How to determine the battery capacity

Capacity is one of the main indicators of quality batteries, which shows the amount of energy contained in them. In the process of operation, this energy decreases. To determine how much will last the battery in several ways.
Instruction
1
To determine the capacity of the battery you need to purchase a special device or ask it from their friends. Then proceed as follows. Fully charge the battery, and then using the current, use it. Note the time during which it will discharge the battery.
2
Perform a calculation that will allow you to learn the battery capacity. The strength of the current used to discharge the battery, multiply the time spent on her complete devastation. The product of these two quantities is the amount of energy that can contain a battery. Keep in mind, likewise you can determine the capacity of any battery, including car battery and an ordinary battery.
3
Use another way to know the battery capacity. But note, for this you need a special scheme through which it is possible to discharge the battery through the resistor when the voltage magnitude not exceeding 1 volt. Next, calculate the amperage by the formula:
I = U/R. For registration of the discharge time, use a regular stopwatch or clock.
4
Be careful using this method. Make sure the battery is not fully depleted. To avoid this, use solid state relays, which can be used to disconnect the battery at precisely the moment when the voltage drops to the minimum mark.
5
One of the easiest ways to determine the capacity of a battery is the device information is specified on the tag manufacturer. Grab your battery and carefully inspect its surface, which should be displayed all the necessary information for operation of the device. If there is no sticker or it is jammed, follow the operations described above.
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