The Tesla Powerwall home batteries launched last year andproved to be so popular that the manufacturing company hardly has any left.

The home batteries are in such high demand that they close in to $1 billion in sales and are sold out until the summer of 2016.

The Powerwall comes to meet the needs of home owners who rely on solar panels. Tesla's home batteries allow the solar energy to be stored for longer periods of time. It is so reliable that it even powers your home after the sun has set.

Elon Musk, the CEO and founder of Tesla Motors, lately answered some questions at a Q&A session in Paris and confirmed exciting news. He told the media that even if Tesla is still shipping the first Powerwall variant, his company is working hard to roll out an even better model.

"We are coming up with the version two of the Powerwall probably around July or August of this year," Musk says.

A range of "moderate improvements" are expected to land on the new model of Powerwall, one of which would be a longer life cycle.

At the moment, Tesla builds the home energy storage devices on Panasonic batteries. However, the second generation of Powerwall will pack Tesla's own batteries, which will be manufactured at the company's Gigafactory.

The Nevada industrial complex should upgrade Tesla's productivity levels to a point that will allow it to fill the back-orders and face the surging upcoming demand.

Many Powerwall clients are homeowners who use solar panels for heating and power, but the enterprise sector started to show interest in the home batteries, as well.

The consumer model, first generation, has a price point of $3,000, for which it brings 7 kWh and daily cycling. The better existing model costs $3,500 and comes with 10 kWh and support for weekly cycling. This makes it the go-to choice for backup chores.

Using the Powerwall has a number of perks. To summarize, users are able to shift electricity loads to and from the battery to fit their needs and they can program the battery to store surplus solar energy. What is more, the Powerwall acts as a hefty backup power source.

With the tremendous success of existing Powerwall home batteries, it will definitely be exciting to see what the next generation brings to the table.

To get a better idea of Tesla's plans, check out the Q&A with Elon Musk in the video below.