BMW will show off an electric Mini at the upcoming Los Angeles Auto Show, and will lease 500 of the battery-powered beasties to interested individuals or businesses in California, New York and New Jersey in 2009.

The Mini E is clearly a bit of a bodge job, and is probably more about PR and fact-finding for BMW than a serious transport proposition. The lithium-ion battery takes up what used to be the rear passenger seat area, for example.

The battery is interesting. We’ve read rumours that it might be related to the Tesla Motors power pack, since it is constructed from a large number of small cells assembled in sub-units. However, the numbers suggest that the two are not related. Tesla uses 99 bricks of 69 cells each to give its Roadster a total of 6,831 cells. BMW has used 48 units of 106 cells each to give the Mini E its grand total of 5,088 cells. Similarly, Tesla claims 56kWh total energy storage, while the BMW quotes 35kWh - giving the German runabout a much lower energy density per cell.

But while the battery is different, the thinking behind it is not. BMW is thus likely to gain large-scale data about the viability of the big-box-of-batteries approach at the same time as, or perhaps ahead of, its upstart electric car rival.

The Mini E also bears no resemblance to the electric Mini concocted by PML Flightlink to show off its compact in-wheel motors. BMW’s new baby uses just the one motor to drive the front wheels through a single-speed gearbox.

Meanwhile we are left to speculate about whether the Mini E will come to Europe. BMW UK seems to think it likely, but has no dates or real plans to talk about.

We’re also left wondering if this is the electric car that BMW top brass began murmuring about in February, triggering much speculation about a third brand and sub-Mini city cars. If it is, it’s a bit of a let-down. But then, as we said above, the Mini E is clearly a case of research in progress. Let’s hope the experiment bears worthwhile fruit.