Guide to Li-ion Rechargeable Battery

The mAh capacity specification refers to the available storage capacity of a given battery. A battery with a capacity rating of 1800 mAh could provide 1800 mA of current for one hour. Higher mAh values for the same battery type generally mean longer run times. This does not apply when comparing different battery types. This means that you cannot predict how long your electronic device will run based on the capacity rating of a battery alone. If you’re powering high-consumption electronic devices like digital cameras, computer peripherals, or portable music players, an alkaline battery will deliver only a small fraction of its rated capacity. For example, AA alkaline batteries typically have a capacity of over 2,500 mAh, while AA NiMH batteries have a capacity of only 1,200 to 2,000 mAh. But when it comes to powering an electronic device like a digital camera, the NiMH batteries can often run the device three or four times as long. Even comparing the capacity values of similar battery types is often not possible because different manufacturers may measure battery capacity in slightly different ways. A NiMH or NiCd battery is likely to be much closer to its rated capacity when running high power devices. Alkaline batteries have a high rated capacity, but can only deliver their full capacity when power is slowly consumed. This means that a NiMH battery with a rated capacity of 1,200 mAh can take many more photos than an alkaline battery with a rated capacity of 2,800 mAh.