We’ve covered the new BMW i3’s revolutionary mass-produced carbon-fibre structure last week, and almost immediately a few readers raised the question on whether or not it can be repaired in case of a crash. In motorsports, carbon-fibre is known to shatter and crumble on impact; will it be the same with the BMW i3?

In short, no, it won’t. The carbon-fibre construction used in the i3 is very different to that used in motorsports. It’s built to be impact resistant, very rigid and lightweight, yet crucially, BMW maintains that its reparability has not been compromised. In fact, the company claims that the i3’s accident repair costs are similar to those of a BMW 1 Series – the cheapest of its extensive model lineup.

Carbon-fibre has impressive energy absorption properties and is very damage-tolerant. BMW claims that it is the lightest material that can be used in car body construction without impairing safety. The carbon-fibre and aluminium LifeDrive concept in the BMW i3 has partially surpassed comparable steel designs in BMW’s internal crash tests.

There are crash-active aluminium structures at both ends of the i3, designed in such a way that less body deformation occurs in crashes compared to similar sheet steel bodies. Furthermore, the “cocoon effect” of the carbon-fibre shell ensures that the doors can be opened without any problems.

Several repair sections are defined into the side frame. If a damaged side sill needs to be replaced after a side impact, it will simply be cut out (along many predetermined separation points) and replaced with a new part. It’s no more complicated than a simple cut and paste job, but as goes without saying, if can only be done by an authorised BMW i workshop.

The i3’s class leading safety measures extend to small or minor accidents too. It is equipped with screw-/clip-on plastic platings all around, so small bumps are absorbed without leaving dents. Plus, compared to metal parts, damage to the paint does not lead to rusting.


BMW’s usual reliability and safety standards extend to the electrical components of the i3 too, of course. The lithium ion (Li-Ion) battery is designed to last at least as long as the full lifetime of the vehicle, so there’s no threat of having to replace the (costly) cells a few years down the road.

The battery’s longevity and reliability is extended through intelligent battery management and an effective heating/cooling system bespoke to the i3. It uses the air-con system’s refrigerant to cool the high-voltage battery directly, offering optimal efficiency in comparison to water or air-cooling. The system goes without additional fans or pumps, further reducing weight and installation space.

As such, it operates independently of fluctuating outside temperatures, benefitting the suitability for daily use, long-term stability and lifespan of the battery. On top of that, three safety levels including both software and hardware deactivation mechanisms secure the entire electrical system reliably. In the highly unlikely event of a fault, defective components can be identified, and individual modules or the entire battery (eight modules and 96 cells in total) can be replaced.

The BMW i3’s carbon-fibre construction is more complicated than that of most cars out there, yet it is claimed to be safer than cars its size and is just as economical to repair as standard BMW vehicles. For more on the BMW i3, check out Paul’s extensive launch story on the new electric car, including an in-depth look at its crashworthiness here.