UK participants in the Mini E field trial may have had their new electric cars for just a week, but their rides are already obsolete.

BMW’s second testbed electric car, the ActiveE, appears substantially superior to the electric Mini. And not just because it is built around the larger, 1-Series Coupe body.

The electric Mini took its cues from the Tesla Roadster, using a large, boxy battery made up of thousands of small, cylindrical lithium-ion cells, hijacked en route to their usual homes inside laptops and camcorders. This weighty powerplant was then inserted in the centre of the wheelbase, and the humans and other accoutrements were squashed around it.

The ActiveE, in contrast, offers a layout that you might actually want to live with. It can carry four people and their suitcases, whereas the Mini E could carry two people and their sandwiches. Both cars need to spend substantial time hooked to a wall socket every 100 miles, of course (or, in the real world, about every 85 miles).

The batteries in the ActiveE are bespoke items, built with automotive applications in mind by SB LiMotive – a joint venture between Korean firm Samsung and German parts giant Bosch. Each cell in the new battery is bigger and squarer than those in the Mini E, and far fewer cells go to make up the battery. The cells are arranged into a T-shape, taking the place of a conventional engine, gearbox and prop-shaft, and filling the space beneath the rear benches.

And whereas the Mini E drives its front wheels, here the specially designed motor is integrated into the rear axle, delivering its 170bhp and 250Nm to the rear boots. This is sufficient to move the car’s 1,800kg bulk from zero to 62mph in less than nine seconds and on to a governed 90mph maximum. Having driven the Mini E, which is undoubtedly a quick and agile car, we have no doubts that the ActiveE will be equally eager.

Like the Mini E, the ActiveE is destined to go into limited production for a field trial with both private and commercial customers. No doubt participants will need to be committed to the cause – BMW is likely to levy a substantial monthly charge for taking part in the study.