Understanding Ah, mAh, and Wh in Battery Specifications
In our daily lives, batteries are everywhere—powering everything from smartphones and laptops to electric cars and home energy storage systems. Knowing the capacity and energy of a battery is key to choosing and using these devices effectively. You might come across terms like Ah, mAh, and Wh when looking at battery specs, but what do they actually mean? Let’s break them down.
Battery Capacity Units Explained
Battery "capacity" refers to the amount of charge a battery can store. It’s typically measured in ampere-hours (Ah) or milliampere-hours (mAh), which essentially means "current × time." To visualize this, think of the current as water flowing into a swimming pool, and the battery as the pool itself. The size of the pipe and the flow rate determine how quickly the pool fills up.
Here’s a quick rundown of these common battery capacity units:
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Ah (Ampere-Hours): This is a key indicator of battery performance. For example, a 7Ah battery can provide a continuous discharge current of 0.35A for up to 20 hours (using the formula: 7Ah / 0.35A = 20 hours).
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mAh (Milliampere-Hours): This is one-thousandth of an ampere-hour. So, 1mAh is the amount of charge a 1mA current provides over one hour. A 2,000mAh battery is equivalent to 2Ah of capacity.
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Wh (Watt-Hours): While mAh measures battery capacity, Wh measures the energy. To convert mAh to Wh, you also need to know the voltage. The conversion formula is: Wh = (mAh / 1000) × V (voltage).
If you need to power a lot of devices, consider using high-capacity power stations. They can store a large amount of energy and easily supply power to multiple appliances.