CAP-XX’s latest supercapacitor module supports stop-start (also known as idle-stop or micro-hybrid) vehicles’ batteries by supplying the peak cranking current (up to 300 A) needed for each engine start. In terms of power density, it features 150F at 14 V, and a 4.5-mΩ ESR, providing enough energy to support frequent start cycles. Control electronics include management of stop-start functions, balancing of voltage across each supercapacitor cell, and limiting of battery current during each restart. After module installation, the vehicle battery need only support continuous power functions (e.g., air conditioning, lights, etc.). The battery also charges the supercaps for their first start; once driving, the alternator keeps them charged. The size of the module, which contains six of the company’s thin supercapacitors, approximates six DVD cases.