Today, lithium-ion is the fastest growing and most promising battery chemistry. It has an energy density that is twice that of nickel cadmium. Hence the load characteristics are good. This low maintenance battery, behaves similar to the nickel-cadmium battery. It does not require a scheduled cycling to prolong its life. Its self discharge is less compared to that of nickel cadmium batteries and well suited for modern fuel gauge applications. Despite its overall advantages, lithium-ion has its drawbacks. It is fragile and requires a protection circuit to maintain safe operation. Aging too remains as the main concern for most lithium-ion batteries but most manufacturers remain silent about it. After one year of use, capacity deterioration is seen irrespective of whether the battery is used or not. Batteries generally fail after two or three years.
