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.
How to calculate battery capacity
You will need
  • A device for measuring battery capacity
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.
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).
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.
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.
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 measure capacity

Most often, the need of measuring capacity arises from the owners of vehicles to test batteries. There are some simple steps to correctly measure their capacity.
How to measure capacity
The battery is a chemical current source, in which electric current is generated by chemical reactions in the battery.
Thus, the principle of operation of the battery is a little different from ordinary batteries. Battery capacity is the quantity of electricity which can give a new or fully charged battery.
Battery capacity is measured in ampere-hours or milliampere-hours. So, if the capacity of the battery is 2000ma-HR (milliampere-hours), which means that the battery can give current of 2 thousand milliamps for 1 hour or 200 mA for 10 hours.
To determine the capacity, the battery should first be fully charged, then discharging a given current and to track the time the battery is fully discharged. Then you need to calculate the product of current times the time that battery is dead, the obtained value will be the capacityu of the battery.
Similarly, a measured capacity of the battery. The meaning of the measurement of the battery capacity or battery is that you can find out the time during which the battery or battery completely discharged. The battery will require a recharge and the battery will come to full unfitness.

Advice 3 : 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.
What is the battery capacity
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.
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