Porsche has committed to making electric cars a permanent part of its lineup, but that doesn't mean every model will get an all-electric powertrain.

Batteries are fine for sedans and crossovers, but they're too heavy for the 718 Boxster and 718 Cayman—Porsche's smallest, nimblest sports cars—the automaker's research and development boss said in an interview with Car magazine.

"The additional weight for a sports car, we are not satisfied with today," Dr. Michael Steiner said. However, he noted that Porsche has not made a final decision on an electric sports car.

That didn't stop Tesla from adding a battery-electric powertrain to a Lotus Elise chassis to create the original Roadster a decade ago, although period road testers noted a negative impact on handling.

The automaker is currently testing modified Boxsters with electric powertrains, Steiner noted.

Porsche unveiled an electric Boxster prototype—dubbed Boxster E—in 2011, but the car never made it to production. Apparently unwilling to take "no" for an answer, at least one person converted a Boxster to electric power.

2020 Porsche 718 Cayman GT4

The Boxster E was just one of many teases of an electric sports car by Porsche over the past decade.

A recent report indicated that Porsche parent Volkswagen is also developing a separate electric sports car, which could also form the basis for the next Audi TT.

In addition to the 718 models, Porsche has also gone back and forth over an electric version of the 911.

The 911's iconic status may be a hurdle to approval of an electric powertrain, although a hybrid model is expected as part of a mid-cycle refresh of the current-generation 992 model.

Porsche previously confirmed that its next electric production model will be a variant of the Macan crossover. The electric Macan will launch in 2022, and is expected to replace the gasoline model entirely.