If you look at a AA battery, laptop or phone battery, you can see the inscription, for example, 2000 mAh. Many people know about this designation only superficially, linking the numbers with the battery charge, that is, they think: the larger the number, the longer the device works. But it's not quite like that.
What do the letters mAh mean
Perhaps someone noticed that Wh is indicated on some batteries, and mAh on others. What does it mean? And what's the difference?
Most often, the Wh-designation can be seen on laptop batteries for Dell, and the mAh value - on Asus, Toshiba batteries and devices from other companies. To understand the difference, you need to understand the definitions.
Laptops and phones do not need a powerful battery, and therefore their capacity is measured in milliamp-hours, which are recorded as already known - mAh (but batteries for cars have an ampere-hour - Ah). A milliamp is one thousandth of an ampere. That is, it is nothing but the derivative of current and time.
So, mah - what does that mean? One milliampere hour is consideredmeasurement showing the amount of charge stored in the batteries. 1 mAh - a charge transmitted for an hour through a conductor with a current strength of 1 mA. When the battery has 2000mAh, it will give a current of 2 amps (2000mA) at that hour.
What is Wh
Wh (watt-hour) will give you an idea of how much power is stored in the battery, that is, 1 Wh has a power of 1 watt transmitted for an hour through a conductor. As a rule, the Wh designation is more understandable to gadget users, because it is easier to understand how many hours the laptop will need to work, how long the battery will last.
For example, 90Wh is indicated on the laptop battery. Knowing that 1 watt is consumed per hour, you can calculate the operating time of a laptop that needs at least 60 watts of power to work: 90Wh is divided by 60 watts, it turns out 1.5 hours of operation of an electronic device.
The question arises: where did these 60 watts come from? They are almost always indicated on the laptop power supply in the form of volts and amperes, which must be multiplied with each other - this will turn out the power figure, these notorious 60 or 70 watts.
What is the difference between mAh and Wh. mAh - indicates the amount of charge (current) stored in the battery; Wh - notifies the power that the battery can provide to the device, the same laptop for example.
How to convert mAh to Wh and vice versa
If you look at the laptop battery, you can see that its capacity is indicated there, let's say 5200mAh, as well as a voltage of 14.9 volts (V). What's with all thisdo? Divide 5200 by 1000 and get 5.2 amp-hours (Ah). Then multiply 5.2 by 14.9 and you get 78.48 watt-hours (Wh).
If you need to convert Wh to milliamp-hour (mAh), then you should "go" back. That is, 78, 48 Wh divided by 14.9V - you get 4, 9Ah, which are multiplied with 1000 to get 4900mAh.
What does mAh mean on a battery
As it turned out, mAh is not an indicator of energy, but it is connected with it. Everything becomes clear with simple mathematical calculations.
With a 5000 mAh phone battery and 1 milliamp used, the battery lasts for 5000 hours, with a loss of 2 milliamps it will last for 2500 hours, with 1000 milliamps spent, the battery will last for 5 hours.
Often there are situations when a battery with 6000 mah first gives a current of 6 Amperes per hour, but then less and less, that is, it "sits down". It depends on what tasks are performed on the electronic device. It is known that if you listen to music or watch a video on your smartphone, the gadget will “sit down” faster than when reading an e-book in the same amount of time.
Sometimes on the packaging of electronic devices you can see the value: "2000 mah two cells". What does it mean? mAh to calculate the total capacity of 2000 should be doubled, and the total capacity will be 4000 mah (20002).
What else affects the performance of electronic devices
Much depends on the type of battery - most electronic gadgets today have lithium-iona battery that can be recharged without waiting for full discharge.
In addition, hardware also affects performance: the more powerful the phone, the more mA should be in the battery. For example, one gadget with a 1550 mAh battery can last 5 days without recharging, while another with a 3500 mAh battery will not last even a day.
The display is also a big consumer of energy. Here the secret is in the screen production technology. IPS will require more power than Super AMOLEDs, which are very energy efficient due to the predominantly black color on the screen. Don't discount brightness and resolution.
It is important that your phone has as few unnecessary background processes and services enabled as possible. Fortunately, devices from Sony and Samsung include special utilities in the software that optimize device performance and save energy.
And that's not all: don't forget about the heart of any electronic gadget - the processor, which also loves to eat well.
It turns out that this is not so important if you look at the rest of the characteristics. Therefore, when buying a new device, you should pay attention not only to the battery, but also to the hardware, software and screen type.
What does 10000 mAh mean on a battery
But the real find was external batteries (Power Bank) with a similar capacity, which will become a lifesaver for every traveler when there are no outlets nearby, and the volume of the native battery is small.
If some Power Banks can only charge a couple of smartphones, thenothers handle tablets, laptops, and digital cameras with ease). Accordingly, more powerful devices are those with a battery of 20000 mAh and higher.
The capacity of external batteries is measured in the same milliamp-hours. This parameter determines how many times the device can charge a smartphone or other device. But even if the capacity of 10000 mAh is indicated on the Power Bank, in fact it is smaller, and it is written in small letters that in fact its capacity is less. As a rule, 10000 mAh is 30%, which are "lost" as a result of voltage conversion. The range of gadgets with a powerful battery - 10000 mAh and above is becoming wider.
How long does a 20000 mAh battery last
For example, the usual situation: lost (broken) "native" charger to the gadget. Another was given for use, the output of which indicated "800 mA", but now it is not clear how much to charge it. The phone battery says: 2500 mA, and there is an incomprehensible inscription: Standard charge 18 hr at 200 mA. How to deal with all this? Again, calculations: the battery is able to store 1500 mA of current, which is theoretically issued for an hour until it is completely discharged.
The inscription on the battery indicates that it should be charged with a current of 200 mA for 18 hours, and the charger can output a current of 800 mA. It remains only to calculate the hours: the charging current is 4 times more (800 mA divided by 200 mA), which means that it will take 4 times less time to charge the battery. Thus, it will take 4.5 hours to charge the battery with this charger (10 hours divided by 4 hours).
Ideally, you should buy external batteries with an outstanding current strength of 2A or more, because the output current affects how quickly the gadget charges.
For example, if an external charger has a capacity of 20000 mAh, it will be enough for 17 full charges of the smartphone, but, again, it all depends on the "native" battery.
How to choose a battery for a smartphone
Today, many batteries have a charge controller, which in an emergency (overheating, hypothermia of the battery) will turn off the device. This is great, but when buying a battery, you should focus not only on the controller, and not even on the capacity (however, the more mAh, the better), but on:
- identical with old battery; voltage also matters (on average it is 3.7 V);
- battery type (lithium ion or other);
- warranty (standard - from six months to three years);
- number of times to charge the battery (usually 1000 times);
- strength;
- cost (buying a high-capacity battery for little money will not work: either the seller is trying to cheat, and the battery is of poor quality, or the capacity is lower than indicated).
Also keep in mind that overcharging the battery too often can cause rapid wear.
The article discussed what it means - mAh. We hope the information was useful.
