How to calculate the use time of battery?

Battery capacity is generally calculated in AH (ampere-hours), and the other is calculated in CELL (unit plate) several watts (W).

1. AH (ampere hour), defined in 20 hours standard. For example 7 AH battery is refers to the continuous discharge current of 0.35 A, time for 20 hours.

2. W (power consumption)/CELL plate (unit), as a standard definition is 15 minutes. For example, 1221 W 12 v battery for CELL (6), each CELL power supply 21 W power supply for 15 minutes.

3. The charging time on the basis of 10 hours. 1/10 of the charging current of battery capacity, quick charging will reduce battery life.

Battery capacity unit is the MAH like laptop battery unit is but is the same lip example a piece of mobile phone battery capacity of 1000 MA/H then he to work to the current 1000 MA, the 1 h after you take a look at your cell phone working current X (should have on the manual, the unit should be MA) then you 1000 divided by X, but is generally longer than the actual, the specification is on standby current, but we normally call to play a game this is a very power-hungry.

This answer adopted by Internet users

1, "MAH" is the unit of battery capacity, the Chinese name is called MAH (in measuring large capacity batteries such as lead-acid batteries, for convenience, generally by "Ah", Chinese name is).

1 MAH = 0.001 amperes * 3600 seconds = 3.6 ampere s = 3.6 coulomb

2, the coulomb's power unit, the coulomb is not a basic unit of international system of units, but the international system of units derived units.1 coulomb = 1 amp, seconds.

Transport within 1 s 1 a current of electricity, which is 1 c = 1 a. s.

3, the electrical power calculation formula: P = UI.P is the unit of watts W; In the pure resistor in the circuit, according to the ohm's law in P = U = IR can also get the UI: P = I = U) (U * * IR/R

A, the most direct algorithm:

1, the first to get the current electrical equipment

2, battery capacity to be divided by the current results of electrical equipment is the length can be used

Such as:

A 3000 MAH, the rated voltage of 5 v battery to a 2.5 W power consumption, voltage of 5 v power supply electrical equipment, its theory of hours used for:

I=P/U=>2.5w/5v=>0.5A=>500MA

3000 MAH, the current is 3000 ma can one hour,

3000/500 = 6 hours

Second, through the charge coulomb algorithm

C = IS = > 3 a * 3600 s = > 10800 C coulomb (charge)

10800 c * 5 v = 54000 w power

54000w/2.5w=21600/3600s=6h

, battery working time calculation is as follows:

Battery work time = battery capacity/battery power rating.

Battery capacity and rated power can be read from the battery specification, but the battery power is not always equal to the rated power, at the beginning of the use will be slightly greater than the rated power, later will be less than the rated power, so the work time will be different.

Rated power refers to the power when using electric equipment to work normally. Its value in the rated voltage times the rated current of the appliance. If use the real power of the electric appliance is greater than the rated power, the electrical appliances may be damaged. Working in normal operation conditions, the output power of power equipment or energy the input power of the equipment, often use "KW" as the unit. Also refers to the factory production of the machine in normal work can achieve power. Here's 220 MAH is the total power of discharge Q = It.

So t = Q/I = 220/1.2 = 183 h. in standard state in 183 hours. The 3V in the title is the voltage for normal operation.

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