As the newest carmaker on the block, it's perhaps not surprising that Tesla Motors likes to do things differently.

That includes reaching beyond the automotive sector with its recently-announced plans to sell standalone battery packs for home and commercial energy storage.

Yet that seems to be an idea the world's oldest car manufacturer is pursuing as well.

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Mercedes-Benz now plans to enter the energy-storage business as well.

A division of parent company Daimler has been testing battery packs that can power houses, and plans to launch commercially in September, according to Australia's Motoring.

Like Tesla, Daimler has tested quietly energy-storage systems for some time.

2014 Mercedes-Benz B-Class Electric Drive

The company created a subsidiary called ACCUmotive in 2009 to develop lithium-ion batteries.

It built an energy-storage array that is now operated by German electricity joint venture Coulomb.

The system's 96 lithium-ion "modules" boast a combined 500 kilowatt hours of storage capacity, which is used to stabilize the Saxony Kamenz power grid.

ALSO SEE: Tesla Didn't Invent Home Energy Storage, Has Many Competitors

There are plans to expand this installation to 3,000 kWh of storage capacity.

To date, ACCUmotive has reportedly delivered more than 60,000 lithium-ion cells to customers--which may include Mercedes-Benz itself--and employs more than 250 people.

Now though, Mercedes is looking to enter the commercial energy-storage market in earnest.

2015 Smart Fortwo Electric Drive

It claims to be testing battery packs for "light industrial, commercial, and private" applications, with sizes ranging from 2.5 kWh to 5.9 kWh.

The individual packs can also be combined to provide more storage capacity for a given site, the company says.

MORE: 2016 Mercedes-Benz C350 Plug-In Hybrid: First Details From Detroit Auto Show

Daimler's decision to enter the energy-storage business seems less straightforward than Tesla's.

Tesla's energy-storage plans are fueled by its massive Nevada "Gigafactory," the primary goal of which is to provide large quantities of cheap lithium-ion cells for the upcoming Model 3 electric car.

2016 Mercedes-Benz C350 Plug-In Hybrid

While Daimler currently offers the Mercedes-Benz B-Class Electric Drive, Smart Fortwo Electric Drive, and--soon--a full range of plug-in hybrid models, it probably isn't aiming for the same battery-cell volumes as Tesla.

And without a Gigafactory of its own, it's less clear how Daimler will supply a larger-scale energy-storage operation.

However, a visible presence from Daimler might provide some much-needed competition for Tesla's high-profile Powerwall batteries--and the advantage of a globally known brand name, which none of the newer, smaller companies that sell energy storage batteries can claim.

The possibility of Daimler jumping into the market relatively soon after Tesla's announcement shows just how big a business energy storage could become over the next few years.

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