New Battery Charging Solutions for Li-ion Cells
Over the years, demand for efficient, light, fast-charging, safe, and cost-effective portable power has led to development of many new battery technologies, including nickel-metal hydride (NiMH), rechargeable alkaline, lithium-ion (Li-ion), and lithium-polymer (Li-poly), to name a few.
Generally speaking, these new battery chemistries require more sophisticated charging and protection circuitry to maximize performance and ensure safety. Fortunately, equally advanced semiconductor devices to charge and protect them have also been developed.
This article explores the virtues and limitations of the newer battery technologies. It also investigates and reports on new charging solutions for Li-ion batteries from semiconductor suppliers like Maxim Integrated, Linear Technology, and Texas Instruments.
In the portable electronic equipment space, several new rechargeable battery chemistries have emerged in recent years to compete with the long-favored nickel cadmium (NiCd) technology, which continues to be attractive in applications such as power tools, where high current for short periods is needed and where the low-impedance characteristics of NiCd is desirable.
However, designers of modern portable applications such as smartphones, tablets, and digital cameras are in pursuit of batteries with higher capacity and lower discharge rates as compared to NiCd. In addition, these applications demand batteries that can charge quickly and offer low weight. Battery technologies meeting these requirements include nickel metal hydride (NiMH), lithium-ion (Li-ion) and lithium-polymer (Li-poly). While NiMH batteries feature greater capacity and faster charging, their limitation is a higher self-discharge rate, twice that of NiCd, which is relatively high to begin with (Table 1).
For more detail: New Battery Charging Solutions for Li-ion Cells