Battery stress tests

A fire is burning. Blazing flames are rising upwards and the black smoke above the fire can be seen from miles around. Right in the middle of it all: the battery of a MAN eTruck. Can it withstand the flames? Or will it too begin to burn? Thankfully, this dramatic situation is not taking place in real road traffic, but on a test site, where a team of MAN engineers are performing a “Fuel Fire Test”. The scenario: a MAN eTruck has collided with another vehicle, some leaking fuel caught fire and now the battery is right in the middle of the flames.

“Even under such extreme conditions, the battery should not pose any risk,” explained Christian Pastötter, Battery Validation Team Leader at MAN. “The design must ensure that the battery itself does not begin to burn.” To check this, the team places the battery on a kind of grill and lights a fire beneath it. After one and a half minutes, at temperatures of 800 degrees Celsius, the battery is moved a little to the side and, due to the proximity to the flames, remains exposed to significant heat. In the end, it passes the test: neither the direct flames nor the heat of the fire were able to set it alight.

Bollard vs battery

The bollard test simulates an impact on the battery housing from below, as could occur when driving over a bollard at a speed of 35 kilometres per hour. “Here, the underbody protection must demonstrate that the battery remains intact – i.e., that despite external damage, for example, no electrical faults occur,” said Pastötter. The battery passed this test successfully too.

Not to mention the “Flying Part Test”. In this test, a metal object is catapulted against the battery at 89 kilometres per hour, and the battery must remain in working order afterwards. In reality, a large piece of metal could be kicked up from a vehicle ahead, for example, and hurled against the MAN eTruck.

In addition to road traffic, the batteries also face some challenges through logistics. For example, they could fall from a forklift truck – a scenario tested in the “Drop Test”. From a height of one metre, the testers let the battery fall onto a concrete floor from a slight incline. It handled this situation brilliantly too. “All of the stress tests have shown that our batteries are very robust,” said Pastötter in summary. “Many customers are still a bit intimidated by the new technology. But nobody needs to worry: MAN batteries are safe.”