Standard, non-rechargeable batteries do not give an owner any information about a battery's state of charge (SoC) or state of health (SoH). With standard batteries, nothing about the battery, including its weight, size, shape, color or brand will inform the user about particular points in the battery's lifespan. A smart battery, however, is designed to answer this problem by providing regular information about a battery's SoC and SoH.
Rechargeable batteries are often marketed as smart batteries. A microchip incorporated into a smart battery allows the battery to display information about itself to the user, the device in which it is used or to its corresponding charger. However, many consider complex functions an integral part of what makes a battery smart. Batteries that simply communicate to a charger that they need to be charged to a certain level are not typically viewed as smart batteries.
With that being said, there is no real consensus on what a smart battery actually is. Battery industry organizations and manufacturers of batteries still debate over a precise definition. Problems in marketing often lead consumers to study manufacturer claims and battery capabilities before making a purchase.
It is, however, generally understood that a true smart battery is at least capable of providing SoC information. The way manufacturers and their products choose to provide that information varies. Most companies use chips to achieve this, but they can select a single wire system, a two-wire system or a System Management Bus (SMBus) as conduits to monitor and give SoC information.
Applications and devices that are suited to smart battery usage include laptops, video and digital cameras, biomedical instruments and military devices. The type of smart battery required for a device and its inherent capabilities can vary in function and cost. Low-end smart batteries are likely to cost less, but may not have high functional capabilities or can give questionable SoC readings.
While many consumers may find smart batteries an attractive and resourceful purchase, they must also be made aware of certain disadvantages to purchasing and using smart batteries. Costs for smart batteries can be relatively high, depending on the conduit selected and its required charging system component. In addition, the time and effort involved in periodic calibration may make owning a smart battery cumbersome for the average consumer. Compatibility issues between battery and device or battery and charger may also arise, which can make a purchase much more expensive than initially anticipated.