On Tesla’s earnings call last week, CEO Elon Musk and CTO JB Straubel revealed quite a few interesting new details and speculations about the new battery business, officially launched in May. The company sells batteries to utilities, commercial and industrial companies and home-owners, enabling customers to store energy from solar panels or energy from the power grid to be used for various purposes.

Here is everything we learned on the earnings call about this young, but potentially very large, new business for Tesla:

Already in production: Tesla’s (TSLA) two battery products — the larger Powerpack and the smaller Powerwall — are already being produced in Tesla’s factory in Fremont, Calif, in small volumes. Musk said on the call that production of the batteries will transfer to Tesla’s Gigafactory —the huge battery factory it is building outside of Reno — next year.

Straubel said that Tesla will have the first equipment to make the grid batteries in the Gigafactory installed by the end of the year, with production starting in the Gigafactory in the first quarter of 2016. At that point Tesla will be able to ramp up this business more significantly.

$1 billion with 100,000 reservations: Musk has said in the past that the grid battery business saw so much demand that it “went viral” and was “crazy off the hook.” But Musk clarified some of the numbers behind those statements.

Musk said that Tesla has had 100,000 reservations (these are non-binding orders) for the Powerpacks and Powerwalls, which is worth $1 billion. Those orders could deliver $40 million to $45 million in grid battery sales for the fourth quarter of this year. Sales for the battery business could be “ten times that number next year,” — or presumably $400 million to $450 million in a quarter — said Musk.

Beyond next year, the business could reach “a few billion dollars in 2017.” “It’s sort of growing by a half order of magnitude to an order of magnitude per year,” said Musk. Could it surpass car sales some day? Tesla generated revenue of $955 million in the second quarter, largely off of its Model S sales.

Sold out next year: Musk said with so much demand, Tesla is sold out for all of the grid batteries it could make in 2016.

The breakdown of Powerwall vs Powerpack: Tesla previously said it was seeing 80% of its orders for the Powerpack, the larger battery system geared for utilities and commercial and industrial customers. But Straubel said on the call that the company has “actually been a bit surprised at how strong” interest in the Powerwall has been. Orders are now closer to 70% of the business for the Powerpack, and 30% for the Powerwall.

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Biggest order so far: For the larger Powerpack product, Tesla is commonly selling tens of battery packs, while for the Powerwall, Tesla is selling a single battery or maybe a couple of batteries. But Tesla’s largest order so far for its Powerpack is for 250 of its 100 kWh Powerpacks. That’s huge.

Benefits of Tesla batteries vs competitors: There are a ton of competitors that are already building batteries for the grid and buildings. But according to Musk and Straubel, even the very large battery orders are “plug and play,” meaning a Tesla customer can order a battery system and get everything they need in one order. The low price of the batteries are the foundation of being able to make the system plug and play, said the two executives.

Gross margins: Musk even went into details speculating about the gross margin of the business, answering a question from an analyst. Musk said in the early days he could see gross margins on the order of 15%, but that over time that could grow to 25% to 30%. But Musk emphasized that because the business is so new, there are still a lot of unknowns.