Electrify America has been billed as a charging network to compete with Tesla's Superchargers.

Now it turns out, they may be partners as well.

In an announcement on Monday, Electrify America said it would install Tesla stationary battery packs at 100 of its locations to balance power demand and reduce costs.

DON'T MISS: Electrify America maps out charging network to rival Tesla Superchargers

The problem comes when an electric car—or several—hooks up to a fast charger, especially during the day when electricity demand is already at a peak.

Many, if not most, utilities will institute "demand response" charges (often just called demand charges) to meet—or more accurately try to mitigate—the extra load.

Yet most drivers on long trips, where DC fast charging is needed most, travel during the day, when electricity demand is also highest from factories, cities, schools, and other businesses.

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Installing battery banks will help Electrify America minimize these extra charges by storing excess power generated at night, at low rates, to use during the day when electric rates and demand-response charges are high—just like many electric-car drivers do in their homes.

Electrify America says they expect the Tesla Powerpack batteries to help keep rates lower for electric-car drivers. Demand charges can run between $70 and $110 to charge an electric car—more than filling many cars' gas tanks—and that comes on top of the basic rate for electricity.

“If you pass the demand charge onto the customer in a high-demand charge market.... If you did that, obviously nobody would buy an electric vehicle,” Electrify America’s chief operating officer Brendan Jones told Reuters.

Graphic showing Electrify America DC fast chargers with Tesla Powerpack battery

Graphic showing Electrify America DC fast chargers with Tesla Powerpack battery

Electrify America was set up under VW's court-ordered diesel emissions settlement. The company agreed to spend $2 billion to set up a nationwide network of fast chargers that can charge any type of electric car. That contrasts with Tesla's proprietary Supercharger network, which lets Tesla drivers go almost anywhere in the country but only charges Teslas.

"With our chargers offering high power levels, it makes sense for us to use batteries at our most high demand stations for peak shaving to operate more efficiently," Electrify America chief executive officer Giovanni Palazzo said in a statement. "Tesla’s Powerpack system is a natural fit given their global expertise in both battery storage development and EV charging."

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Electrify America expects to have 484 chargers installed across the country by June. It says it will install the Tesla Powerpacks at 100 of them in areas that have the highest concentrations of electric cars and the highest demand-response charges, primarily on the East and West Coasts. The battery packs can deliver up to 210 kw of power for a charge rate of about 20 miles per minute of charging—faster than any car but the upcoming Porsche Taycan can receive. That would allow three to six electric cars to charge using stored battery power, rather than directly from the grid.

The network will feature locations along well-traveled highway corridors in 42 states, including two cross-country routes, as well as stations around 17 metro areas in the U.S.

Tesla, along with its partner Panasonic, operates the largest factory in the world to produce lithium-ion batteries for its cars. Some of those are used in its stationary Powerwall home batteries and Powerpack commercial storage batteries.