Kessen claims that test results in buses have shown that A123's li-ion batteries last up to six years in stop/start applications. For the sake of comparison, Kessen says that lead-acid AGM batteries have a life expectancy of under two years in grueling stop/start applications. A123's 12V li-ion battery utilizes the firms AMP20 prismatic cells, which have a power density of more than 2,400 W/kg and a nominal voltage is 3.3V.
Recently, A123 Systems entered into a production contract with a major, unnamed OEM on a stop/start system. The battery maker says that it's in the development stages with four other automakers.
[Source: Green Car Congress]