﻿ mAH of a Battery- Explained ﻿

# mAH Specification of a Battery- Explained

The mAH specification of a battery stands for milliampere-hours. mAH is the amount of milliamperes which a battery can provide (to a circuit or device) for the amount of hours specified in its specification.

Thus, a battery if a mAH specification of 1900mAH can provide 1900mA (milliamperes) for 1 hour of time. A battery with a mAH specification of 10,000mA can provide 10000mA for 1 hour of time.

Being that batteries are sources of power and give out current when connected to a closed circuit, all batteries, whether standard or rechargeable, provide current. Being that they provide current, they come with the specification mAH to quanitify the amount of current that they can within an hour's time.

### Battery Doesn't Need to Use All Current in an Hour

Again, mAH, iillliampere-hours, show how many milliamperes of current the battery can supply per hour of use. Again, as an example, a 1900mAH battery can supply 1900mA of current to a circuit for one hour, and then it will have used all of its charge.

Usually a circuit will not demand 1900 mAH of current all at once for operation. A circuit may instead only need 380mA of current for operation. In this case, the battery supplies 380mA for 5 hours, since 380*5=1900. Or for other circuits, it can supply 190mA of current for 10 hours, since 190*10=1900.

The product of the current consumed times the number of hours in use must equal to the mAH specification.

Thus, our same example, of a 1900mAH battery can be used in the following ways, as examples:

3800mA for 0.5hours
1900mA for 1 hour
950mA for 2 hours
475mA for 4 hours
125mA for 12 hours
25mA for 60 hours
etc...

The mAH specification shows how long a battery will be able to last in a circuit, given the circuit's power requirements, how much current the circuit demands.

Being that the mAH is the battery's life in terms of current capacity, the more mAH's means the longer a battery can last, or the more current it can supply in a circuit. So batteries with higher mAH's are more desirable, because they can last for a longer period of time, since they have a higher current capacity.

When considering AA to D cell batteries, AA batteries usually have the shortest mAH life, while D cells have much greater mAH. A AA battery may have a mAH of 2000, while a D cell may have 10,000mAH. For this reason, D cells are physically bigger and are more expensive than C or AA batteries. D cells provide current for a longer period of time than all others.

So, for example, let's say there is a circuit that consumes 200mA per hour. With a AA battery rated at 2000mAH, it can power the circuit for 2000mAH/200mA= 10hours. Now the same circuit powered by a D cell battery rated at 10,000mAH can power the circuit for 10000mAH/200mA= 50 hours. Thus, the D cell can power the circuit for 5 times as much as time as the AA battery cell can. Thus, you can see how higher mAH values are more desirable in circuits, because it leads to longer shelf life for circuit device operations.

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