The capacity of a battery is the amount of energy it contains. The unit of measurement for this value is ampere per hour. Knowing the capacity of the battery, you will roughly know how long it can last you.
Instructions
Step 1
Take a special device to determine the battery capacity. Then do the following. Fully charge the battery and then discharge it using current. Be sure to note the time during which the battery will be discharged. Then do the calculation.
Step 2
Multiply the amperage you used to discharge the battery by the time it took to empty it completely to find out the battery capacity. The product of these two values will be the amount of energy that the battery can hold. In a similar way, you can determine the capacity of absolutely any battery, from a car battery to an ordinary battery.
Step 3
Try a different method to find out the battery capacity. To do this, you need a special circuit with which you can 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. Use an ordinary stopwatch or watch to measure discharge time.
Step 4
Observe an important condition - the battery must not be completely discharged. To prevent this unwanted effect, use a solid state relay. It will allow you to disconnect the battery exactly at the moment when the voltage value drops to the minimum mark. You can also find out the capacity of the battery without using special devices and performing any complex manipulations. As a rule, all the necessary information about the device is indicated on the manufacturer's tag.
Step 5
Examine the surface of the battery. There should be a sticker containing the information required to operate the device. If this sticker is overwritten or missing, you will have to return to the operations described above.
