Chevrolet lead-acid battery pack when compared the
Chevrolet Volt – the first ever extended-range electric vehicle which is built in Michigan at GM’s Detroit-Hamtramck Assembly.
In January 2007 the Volt concept car was first proposed at North American International Auto Show, becoming the first-ever series plug-in hybrid concept car. The EV1’s of the 1990’s were only two seated to reduce weight and to provide necessary room for the lead-acid battery pack when compared the Volt vehicle is a four seated with a rear left gate. The top speed was also increased on the Volt, from 80 miles per hour to 100 miles per hour. The battery pack size was reduced, from about 10.6 cu ft. in volume to 3.5 cu ft.
The Production Design model of Volt was officially announced on 16 September 2008 at the Winter Garden headquarters in Detroit. But this production model differed significantly when to compared to the original volt Design. Once the concept was put into the process of production, General Motors started looking for a partner to develop the Volt’s lithium-ion battery pack.
The Car Manufactures evaluated about 25 distinct battery cell chemistries and constructions from around 2 dozen lithium-ion battery makers around the world. Among them, two companies were selected in June 2007 having most beneficial cell technologies, Compact Power, which uses a lithium manganese oxide cell made by its parent company, LG Chemical, and Continental Automotive Systems, which uses lithium iron phosphate-based cylindrical cells made by A123 Systems. The Compact Power (LG Chem) delivered their finished battery pack prototypes by the end of October 2007 and A123 delivered theirs by January 2008. The 400 pound, T-shaped pack contains 288 of LG Chem’s lithium polymer cells.
The cells are categorized into three primary modules, one forming the bar of the T with the other two running down the center tunnel of the car. The gap between the two central modules provides clearance for the main under-floor cross-member of the Volt structure. The monitoring systems are included in battery packs in order to keep the batteries cool and operating at optimum capacity despite a wide range of ambient temperatures. The volt manufactures decided to use only half of the 16 KWH capacity to reduce capacity degradation and limiting the state of charge up to 80% of capacity which makes the battery pack last ten years and run for 150,000 miles. Another key component used in Volt vehicle is Voltec drive system which has the potential to adapt the vehicles to pure battery electric, to fuel cell-powered or to other sources of energy to create electricity on board, such as engine-generator sets fueled by gasoline, diesel, biodiesel or ethanol fuel.
Regenerative braking would also contribute to the on-board electricity generation. Also, the volt concept featured a 12 gal fuel capacity providing the vehicle a driving range of 640miles total. The Testing process was conducted at the laboratory where the General Motor EV1 program was created.
The first pre-production test car based on the final Volt design was built in June 2009, in Warren, Michigan and by October 2009, 80 Volts had been built and were tested under various conditions. The first factory-built Volt was produced at the Detroit Hamtramck Assembly Plant on March 31 2010 and tested the quality control purposes and production line before regular production began.