The reason behind this is because battery longevity in homes and commercial buildings is apparently a major concern, and to be fair we guess this is a growing market that should not be neglected. According to NEC, this new battery technology will allow the battery to retain 83% of its original charge even after 23,500 charge cycles, which the company is estimating to be about four years worth of use.
The technology behind the longevity of these new batteries is the use of an organic sulfur compound, which reportedly helps to prevent the buildup of internal resistance in lithium batteries. This buildup is what causes conventional lithium batteries to lose its power output and life span over time. Now if only NEC were to take that technology and focus it onto our smartphones and tablets, and maybe we could go back to the old days of the feature phone, whose batteries are usually capable of lasting us a good many days even with moderate usage.