BMW i3 (120 Ah) driven: little EV, bigger battery

Another new i3?

Yup, another. In its brief life the i3 has had an improved battery, a facelift, and a warmed-over ‘s’ version. And now both the normal i3 and the i3s get a bigger-capacity battery again.

How big?

BMW calls it 120Ah. Twice the capacity of the original i3, and so roughly double the range, all done by improving the battery’s internals, at no increase to its size or weight. The Renault Zoe has done the same thing over the years, and the Leaf is about to.

BMW i3 and i3S 120Ah (Image: BMW Group)

BMW i3 and i3S 120Ah (Image: BMW Group)

But Ah (amp hours) isn’t a proper measure of the energy it can store, unless you know the voltage. What you need to know, then, is the gross energy storage, which is 42.2kWh (kiloWatt hours).


You can compare that with a Nissan Leaf (40kWh) or Hyundai Kona Electric (64kWh in its top version). Think of those energy numbers as the size of the electric tank, just as you’d look at the size of the fuel tank in a combustion car.

But even that isn’t the whole story if you want to know the range. As with petrol cars, you need to know the efficiency too. Sort of electric mpg.

So how does the i3 really do?

It’s pretty efficient because it’s light – under 1,300kg is good for an EV – and aerodynamic and rolls on tall skinny tyres. Put all that together and you have an efficiency of around 4.4 miles/kWh.

That gives a range of about 180-193 miles WLTP. The i3s is the slightly less efficient one of the pair.

Enjoy it?

Yup. The new i3s is slightly more powerful than the i3, at 183bhp vs 170. Torque is up from 184lb ft to 199. Hardly enough of a difference to matter. What you will notice is it sits on a wider track and firmed-up springs, anti-roll bars and dampers.
The result is it’s the most fun to drive of all the affordable EVs. The Leaf is soft and gentle. The Kona is torque-steery and a bit ragged, if quick. The i3s is also quick – doing 0-62 with zero fuss in 6.9 seconds. And it’s quite a fun steer, its front wheels gripping decently (the original i3 understeered) and its rear ones getting the power down well. You can lean on it in corners and feel it working beneath you. Sure, it’s tall so it pitches and bobs around when it’s bumpy, but even so, I had a laugh.

Which did what to your range?

OK, tore a bit of a hole out of it. I got about 135 miles-worth out of a charge, driving like I stole it, so was doing only 3.3 miles/kWh. But be aware I’d earlier driven down the same road – in Portugal – in a new 320i and got about 20mpg. There are absolutely no straights, and absolutely no traffic, for endless mile upon fabulous mile. Hills, hairpins, tight esses, the lot.

Read more: Top Gear

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