Development of the Opel Ampera-e: This is where the battery gets stressed

G eneral Motors has a torture chamber for batteries. There, the batteries of Chevrolet Bolt and Opel Ampera-e are subjected to the toughest stress tests. Apparently with success: there is probably a volt battery that still has its original capacity after around 500,000 kilometers.

First there is this huge parking lot, a wide area full of pickup trucks and US sedans. Sure, this is Motor City and we're visiting General Motors' development center. Pickup trucks are as popular in the US as the VW Golf and BMW 3 Series are in Germany, they each lead the registration statistics.

However, we are here to see the battery laboratory, which is the heart of the new eco Spearhead developed and tested by GM: The batteries for the electric cars Chevrolet Bolt and Opel Ampera-e. And the battery laboratory here is the largest in the world, as they emphasize again and again at General Motors: Around 150 employees research batteries in an area of ​​8,000 square meters - and come to work with gasoline dinosaurs.

Since 2008, GM has been working for the battery lab spent $ 52 million. The result is a sophisticated torture chamber for the sensitive cells. Because they prefer to have a temperature of 20 degrees, resent moisture, get tremors when shaken and cannot tolerate charging stress. And what are the developers doing at GM? Think of chambers in which individual cells or entire batteries can be shaken or charged and discharged as quickly as possible, while the temperature and humidity can also change.

Torture chamber instead of mules

The largest and meanest chamber is about twice the size of an Ampera-e, stands on movable stilts and is painted blue: In here, entire batteries are shaken at changing temperatures while they are constantly being charged and discharged. It goes without saying that the humidity is not always constant. Advantage of the torture chamber: “We don't need mules,” explains a test engineer. That saves six to eight months. Time that would otherwise be test drivers in “mules”, ie carrier vehicles with camouflage optics and technology to try out.

The batteries are built at LG Chem in Michigan. “What LG Chem is good at is building batteries. The know-how of how a battery behaves in a car comes from us, ”explains Ralf Hannappel, who is responsible for the electric car program at Opel. The charging cycles add upMegawatt: In ten years, the GM developers calculate that 50 megawatts will flow through a battery.

Good long-term experience

So far, the batteries lasted 200,000 miles, the target was actually 150,000 miles. The engineers know of a Volt customer who has driven 300,000 miles so far and has the same electric range as on day one. So far, none of the tested batteries has reached the wear limit - 30 percent loss of capacity.

Skeptical operating instructions

From this point of view, the note in the American operating instructions appears a bit exaggerated: There, on page 322 that the battery can decrease by 10 to 40 percent within the warranty of eight years and 160,000 kilometers.

Opel explains: “Our experience with the more than 100,000 volt and Ampera vehicles that are now on the market shows that, apart from minimal deviations, our batteries last longer than the vehicle Stable across the board in terms of range and capacity. ”In any case, only 80 percent of the total capacity is being used, but the possible reduction relates to 100 percent. Another reason for the notice is not a technical one, but the strict US product liability.

General Motors builds the electric car as the Chevrolet Bolt and Opel Ampera-e in Orion, Michigan. Ronald Reagan opened the plant in 1984. The motto of the plant, “Build it like we own it”, obliges the 1,200 employees to work as carefully as if they were building their own car. Will they soon switch from their pickup trucks, which are parked outside on the company premises, to an electric car?

Production with conventional compacts

Ampera-e and Bolt share the production the compact model Sonic, which is sold in the USA as a sedan and hatchback. GM has invested 160 million US dollars in the production of the two electric models. In one-shift operation and normally, the plant can build 300,000 cars a year, says plant manager Jim Quick. Normal operation means: no start-up phase for a new model. Production of the Ampera-e has already started, Opel logos can be seen again and again between the Chevy Bowties.