First Volt battery pack of the line – Click above for high-res image gallery

It was exactly three years ago today that the original Chevrolet Volt concept rolled onto the stage at the 2007 Detroit Auto Show. Last summer we visited a facility in Brownstown Township, MI that General Motors had chosen as the location for production of battery packs for the production Chevrolet Volt. In the intervening five months, GM has been busy installing production equipment in the formerly empty building. Today GM invited the media back to Brownstown to watch the first "official" pack roll down the assembly line. Unfortunately, the usual self-congratulatory array of federal, state and local politicians joined the party – but when a facility's existence depends on their largess with tax dollars, it's pretty inevitable that they'd show up.

The battery packs that are being produced – starting today – are full production hardware specification units, but GM engineers are still tweaking the management software in an attempt to maximize range and lifespan. Between now and November, the plant will be producing several hundred packs that will be used for a variety of development tasks. Some will be heading straight into the cyclers at the test lab in Warren, MI. Most of the rest will be going into the pilot and production verification Volts that will begin rolling out of the Detroit Hamtramck assembly plant by April. We've got more details after the jump.

Related GalleryFirst production Volt battery pack off the line

[Source: General Motors]

The 160,000-square-foot Brownstown plant is starting off with 25 employees assembling the packs; that number will grow as production ramps up. GM officials declined to say exactly what the capacity of the plant is right now, but did say that there is plenty of flexibility to add additional shifts and speed up the build rate. There is also plenty of empty floor space available in the building to add more equipment if needed.

The assembly process is broken down into three main areas, starting with module pre-assembly where the cells are installed into one of the three modules that make up the pack. From there, modules are installed into the main case. All the welding of connections is done by automated equipment to ensure quality. Finally, in the pack main line, all the remaining systems are connected and the packs are tested. Testing includes both electrical and electronic integrity as well as mechanical leak testing (the pack is liquid cooled).

We had a chance to talk with GM's battery director Denise Grey about the current state of battery development. Packs and cells are still being tested around the clock at the Warren, MI battery lab. Over the Christmas holiday, the test cells were running in automatic mode with only a skeleton crew coming in to check that everything was okay on a daily basis. The test equipment in the lab is able to automatically notify the engineers in the event that anything unexpected happens.

We asked Grey about the cost of the batteries since this remains one of the big issues in making the Volt a big seller. Many estimates have put the cost of automotive lithium ion battery systems at up to $1,000/kWh. However, Grey echoed what program management VP Jon Laukner told us previously: The current cost of the Volt pack is much lower than that. While neither would be nailed down on specifics, they indicated that the cost was currently around $500-600/kWh, which puts the 16 kWh pack in the $8,000-9,500 range. Grey tells ABG that GM is working closely with suppliers to cost optimize all of the pack's components and hopes to hit the US Advanced Battery Consortium target of $300/kWh by 2015.

Finally, we asked Grey and spokesman Rob Peterson about the comments made by Chairman/CEO Ed Whitacre the day before about launching the Volt earlier than November. At this stage of the program, it is extremely difficult to pull much of anything ahead by much. As development is completed over the next several months, a lot of safety and emissions certification testing must be completed, all of which takes time. Whitacre asked the team if they could pull the Volt launch up, but it is unlikely that it will appear any sooner than November 2010. At best, the car might be in some showrooms a few weeks earlier than planned, but certainly not months sooner. Nonetheless, Peterson emphasized that by the end of 2010, Chevrolet will have "well over 1,000 Volts" on the road, including the pilot build and production verification vehicles that are coming out this summer.