Tesla Motors CEO Elon Musk says the company is "about to end range anxiety" for its electric car drivers with an announcement today.

In a tweet Sunday, Musk said the solution would be a software update that would be applied remotely for all Model S cars — its all-electric sedan. Details are expected to be unveiled at a press conference at 9 a.m. PT (12 p.m. ET).

Electric car batteries have a limited range and can take a long time to recharge compared to refuelling a conventional car with gasoline. Because of that "range anxiety" is often considered a major reason why consumers are slow to switch to electric cars.

The battery range of Tesla's Model S is already very high for an electric car — between 335 and 435 kilometres, depending on the model.

The Palo Alto, Calif.-based company has also been building a network of fast chargers across North America, and is offering battery pack swaps between San Francisco and L.A., a drive of more than 600 kilometres. Musk said that "seems to be working well" but "supercharging is the future, for non-commercial traffic."