BMW is already making some rather grand claims for its i4 all-electric four-door saloon, long before the car is actually due to go on sale. Although we won't see i4s rolling into dealerships before 2021, BMW is already saying that it's going to achieve Tesla-busting performance from an unusually small battery.
That battery is an ultra-compact, flat (so that it fits under the floor) stack of lithium-ion cells. The Munich company says that it can squeeze in more power cells per module, and has more flexibility with how those modules fit together, allowing it to make major improvements in range and performance.
That range figure is being claimed as ‘around 600km’ while performance, from a two-motor setup giving the i4 530hp, will be in the order of a 4.0secs 0-100km/h sprint, and a top speed of more than 200km/h.
All of that is coming from a battery pack with just an 80kWh capacity. Now, that’s still not small, but it is less than the 90-100kmWh packs used by most of the competition to achieve similar, or even inferior, performance.
The battery pack is also not that hefty - 550kg isn’t, perhaps, size zero, but it’s fairly trim for a high-end battery with current technology. They’re compatible with the latest 150kW ultra-rapid chargers, and BMW claims that you can top them up by 100km of range in just six minutes using such a charger.
It’s all part of BMW’s fifth-generation battery and motor family, a modular set of electric car components which can be scaled down (for, say, a plugin-hybrid model) or scaled up for a fully-electric, high performance, model such as this. BMW claims that these new batteries: “will no longer require materials categorised as rare earths.”
In the debit column, however, they do still require copious amounts of lithium, manganese, nickel, and especially cobalt, all of which raise their own environmental and ethical issues when ti comes to mining and refining.
The i4 will use the same CLAR platform as the current 3 Series and next year’s new 4 Series, and will be a four-door coupe in the mould of the current 4 Series Gran Coupe. Early renderings and sketches show a sleek, slinky four-door, albeit one with the controversial ‘big nose’ styling as essayed by BMW’s 4 Series Coupe Concept displayed at the recent Frankfurt motor show.
Before the i4 goes on sale, we’ll have a chance to sample BMW’s fifth-generation batteries and motors; they will make their on-sale debut in 2020’s iX3 - an all-electric version of the X3 SUV. BMW hasn’t yet released any performance or range details for that car, other than to say that it’s likely to have a 450km range from a ‘more than 70kWh’ battery pack.
