Just like old tyres, used car batteries are becoming a millstone around the necks of manufacturers.

In Germany Audi has begun testing used lithium-ion batteries in factory vehicles at its main Ingolstadt plant.

Because they still have a large part of their original capacity, an interdisciplinary project team is investigating how batteries can continue to be used sensibly.

The batteries come from Audi vehicles such as e-tron test vehicles and hybrids such as the Audi A3 e-tron and Audi Q7 e-tron.

A number of other advantages have become apparent too during the test phase.

Fork-lifts and tow tractors have until now been powered by traditional lead-acid batteries.

When the batteries need to be recharged, the battery packs weighing up to two tonnes have to be removed from the vehicles and connected to a charging station for several hours.

But lithium-ion batteries can be charged in the vehicles in breaks between shifts, saving space and eliminating the effort required to remove and replace the batteries.

Audi says it would save millions if it converted its entire factory fleet to lithium-ion batteries at its 16 production sites worldwide.

“Every lithium-ion battery represents high energy consumption and valuable resources that must be used in the best possible way,” Member of the Board of Management for Production and Logistics, Peter Kössler, said.

“For us, a sustainable electric-mobility strategy also includes a sensible second-use concept for energy carriers.”

The driving characteristics of vehicles actually improve with the recycled batteries.

They can keep a constant speed, even on ramps – vehicles powered by lead-acid batteries cannot do this.

In addition, regular charging during breaks prevents downtime during working hours.

The battery pack of an Audi e-tron for example consists of 36 individual battery modules.

After batteries are checked, they are re-installed in new trays, with 24 modules in each.

This has the same dimensions and weight as the previous lead-acid batteries, so the company can continue to use the same vehicles without any major investment.

This pioneering project is one of many that demonstrate Audi’s commitment to the sensible and efficient further use of batteries from electric cars.

It is also conceivable that used battery modules could be used in mobile charging containers for electric vehicles or in stationary energy- storage systems.

Audi is also developing recycling concepts, retrieving valuable elements from batteries at the end of their usable lives to be used again in new products.

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Riley

Chris Riley has been a journalist for almost 40 years. He has spent half of his career as a writer, editor and production editor in newspapers, the rest of the time driving and writing about cars both in print and online. His love affair with cars began as a teenager with the purchase of an old VW Beetle, followed by another Beetle and a string of other cars on which he has wasted too much time and money. A self-confessed geek, he’s not afraid to ask the hard questions - at the risk of sounding silly.