How is the battery power be calculated?

For example: a 12-volt battery with less than 20ah may not work.

20ah is the capacity of the Lead acid battery or Lithium Battery, not the power. If the current is constant, the larger the capacity, the longer the power supply can be used.

20ah means that when the battery output current is 20A, it can be used for 1 hour, can also be understood as when the battery output current is 2A, it can be used for 10 hours, etc. So the current time is 20.

If the device requires a high-capacity battery of 20Ah to operate, it means that the operating current of the device is high and the small-capacity battery may not be able to withstand the high current. If the low-capacity battery can withstand the driving current of the unit, it will be able to drive. Just like you can't run an electric bike with a dozen number 7 batteries connected in series.

This is the capacity of the battery, not the power, i.e. a certain power can make the electrical working time, the length of the working time depends on the size of the electrical power. How is the battery capacity calculated?

Using a 12-volt battery with less than 20ah may not work.

20ah is the capacity of the battery, not the power. If the current is constant, the larger the capacity, the longer the power supply can be used.

20ah means that when the battery output current is 20A, it can be used for 1 hour, can also be understood as when the battery output current is 2A, it can be used for 10 hours, etc. So the current time is 20.

If the unit requires a high-capacity battery of 20Ah to drive, this indicates that the unit's operating current is high and the low-capacity battery may not be able to withstand the high current. If the low-capacity battery can withstand the driving current of the unit, it will be able to drive. Just like you can't run an electric bike with a dozen number 7 batteries connected in series.

This is the capacity of the battery, not the power, i.e. a certain power can make the electric working time, the length of the working time depends on the size of the electric power.

In addition to 100Ah, the battery also needs to know the voltage. The battery can operate for one hour at 100 amps, depending on the voltage of the battery. For example, a 12V battery can run a 1200 watt appliance for one hour at 100 amps and 10 hours at 10 amps. It is the amount of current used that determines the runtime.

Instead of talking about power, the battery talks about "milliampere-hours" or how long it can be discharged, which is its power capacity. The new standard No.5 dry cell has a voltage of 1.5V and an internal resistance of about 1 ohm. The voltage is reduced as it discharges. When the discharge current reaches 500 milliamperes, there is a voltage drop of 0.5 volts and the output voltage is only 1 volt. The higher the discharge current, the lower the total discharge quantity and the shorter the life of the battery. Shorter continuous discharge life.

1V.mA.h=1V*10^-3A*3600s=3.6V.A.s=3.6J

Let's explain in terms of units

The unit of power in watts (W), given by P=UI, 1W=1 v.A (one watt equals one volt). Ann)

Battery capacity in mA.h (MA. When)

Obviously these two parts are different.

Keep looking for connections:

Electrical energy Joule (J)

W is equal to Pt

1J=1W.s=1V.A.s (One coke is equal to one volt-ampere second)

If the voltage of the battery is known, multiply the voltage by the capacity of the battery and see what you get: in V.M.H.

In fact, the unit is essentially the same as that of electrical energy.

1 V.MA. H = 1 v * 10 ^ - 3 a * 3600 s = 3.6 V.A.S = 3.6 J

A battery is an energy storage device, there is no power, it has a rated capacity, in Wh watt-hours, which you get by multiplying the voltage by the capacity.

"12V12AH battery" doesn't mean that its power is 12*12=144 watts!

"12V12AH battery" refers to the capacity of the battery. That is, the rated working voltage of the battery is 12 volts, if the discharge current is 1 amp, it can be used for 12 hours; if the discharge current is 0.1 amp, it can be used for 120 hours; if the discharge current is 0.5 amp, it can be used for 24 hours; and so on.

The battery also has an indicator, the rated operating current. In general, do not exceed the rated operating current, the battery life will be long, otherwise the life will be short.

"Connected to a 300W lamp", the discharge current of the battery must be :I=P/U=300/12=25 Amps. If it does not exceed the rated current of the battery, you can use it. You can use it; beyond that, or much beyond that, you can't use it.

If it can be used, the time used is probably: 12 amh /25 amh = 0.48 hours [Considering the inverter itself and the battery itself and the line is a loss, it is less than 0.48 hours.

1, "mAh" is the unit of battery capacity, the Chinese name is called milliampere (in the measurement of large capacity battery such as lead acid battery, for convenience, generally use "Ah" to indicate, the Chinese name is one hour).

1mAh=0.001 Amps *3600 s =3.6 Amps =3.6 Coulombs

2. Coulomb is a unit of electricity. Coulomb is not the base unit of the International System of Units, but the special unit of the International Unit. 1 coulomb is equal to 1 ampere-second.

1A current The amount of electricity transported in 1s, i.e. 1C=1A-s.

3. Power The formula for calculating electrical power: P=UI. P is in watts W; in a pure resistive circuit, according to Ohm's law, U=IR can be substituted into P=UI: P=I*IR=(U*U)/R

First, the most direct algorithm:

1. Get the current of the electrical equipment first

2. Divide the battery capacity by the current of the device

For example:

A 3000mAH Lithium Polymer Battery with a nominal voltage of 5V powers an electrical device with a power consumption of 2.5W and a voltage of 5V. Its theoretical life is

I = P/U = = > > 2.5 W / 5 V 0.5 A = > 500 mA

3000mAh, that's 3000mA for one hour,

3000/500 equals 6 hours

Second, using the Coulomb charge algorithm

C=IS=>3A* 360s =>10800c coulomb (amount of charge)

10800c*5V=54000W electrical energy

54000 W / 2.5 W = 21600/3600 s = 6 hours