Sales of plug-in electric cars in the U.S. had a low-to-average month in September, with the sole bright spot being the astounding sales of the BMW i3 electric hatchback.

Two new 2016 models, the entirely redesigned Chevy Volt and the longer-range 107-mile Nissan Leaf, should start this month, but last month's sales likely included selldowns of their predecessors as buyers waited for the new and more desirable versions.

DON'T MISS: Plug-In Electric Car Sales In August: Calm Before The Storm?

Remarkably, the BMW i3 was apparently the highest-selling electric car in the U.S. last month, with a total of 1,710 deliveries.

That's its highest month ever, and it brings this year's total to 7,893. Since the i3 went on sale in May 2014, BMW has sold a total of 13,985 in the U.S.--in both battery-electric and range-extended versions.

The i3 outsold both the Chevy Volt--at 949 units--and the Nissan Leaf, whose sales of 1,247 were about average for the year.

2016 Nissan Leaf

2016 Nissan Leaf

For the first nine months of 2015, GM has delivered a total of 9,264 Volts and Nissan has sold 13,630 Leafs.

Sales of the Tesla Model S, the other high-volume plug-in car on the market, are not reported by its maker, Tesla Motors [NSDQ:TSLA].

That company also delivered its first six Model X electric utility wagon models in a highly publicized ceremony in California last week, though the company says that volume production of the Model X won't begin until sometime early next year.

ALSO SEE: Will 2015 Plug-In Electric Car Sales Exceed Last Year's Total?

Among the three higher-volume plug-in hybrid models, Ford delivered 808 Fusion Energi mid-size sedans and 719 C-Max Energi compact hatchbacks, bringing those models' nine-month totals to 6,899 and 5,678 respectively.

Sales of both models are down on the comparable period last year, perhaps owing to continuing low gasoline prices.

Sales of the Toyota Prius Plug-In Hybrid continue to fall; September's 216 was even lower than August's lowest-ever 344, bringing the 2015 total up to 4,034 as the model winds down after production ended this summer.

2016 Chevrolet Volt, first drive in California, July 2015

2016 Chevrolet Volt, first drive in California, July 2015

Like the Honda Accord Plug-in Hybrid, now off the market, it can be considered on its last legs.

(Other plug-in models no longer on sale include the Honda Fit EV and the Toyota RAV4 EV, both compliance cars.)

Among lower-volume plug-in hybrids, the pair of Porsche E-Hybrid models included 41 Panamera sedans and 61 Cayenne SUVs, bringing their 2015 year-to-date totals to 330 and 715 respectively.

UPCOMING: 2016 Nissan Leaf Offers 107-Mile Range With 30-kWh Battery; Leaf S Unchanged

BMW moved another 182 i8 gull-wing plug-in hybrid sport coupes, for a nine-month total of 1,342, and Cadillac's 36 more ELR sales brought that star-crossed model's 2015 deliveries to a not-very-impressive 740.

Among the battery-electric vehicles, 343 Volkswagen e-Golfs found homes free of the taint of the VW diesel-emission scandal engulfing the U.S. unit of the only volume German maker left in the US. That's a nine-month total for the e-Golf of 2,555 compact electric hatchbacks.

Similar in form but more expensive, the Mercedes-Benz B-Class Electric Drive sold 147 units in September, for a yearly total to date of 1,687.

2015 Smart Fortwo Electric Drive

2015 Smart Fortwo Electric Drive

Its corporate stablemate, the tiny Smart ForTwo Electric Drive, saw sales fall to 94, for a 2015 total of 955--and Mitsubishi moved 3 more units of the poor little i-MiEV electric car, bringing its 2015 total to a sad 93.

Wrapping up the list, 145 Ford Focus Electrics found buyers, for a nine-month total of 1,267, right in compliance-car territory.

With its 74-mile range and no DC quick-charging ability, the Focus Electric is likely to suffer against the uprated 2016 Leaf; Ford's sole battery-electric offering remains largely unchanged as it enters its fifth model year.

MORE: 2016 Chevrolet Volt - full review:

Chevrolet sold either 150 or 157 Spark EVs--we're still working with the company on that one, and we'll update this piece when the number resolves itself.

Finally, monthly sales data is not provided by the makers of the Fiat 500e or the Kia Soul EV.

Here's hoping that the arrivals of the 2016 Nissan Leaf and Chevrolet Volt give the rest of the year a bit of a sales boost.

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