Tesla is integrating Maxwell’s ultracapacitor business months after the acquisition, several employees confirmed, but it’s unclear if it’s only to comply with existing contracts or if they plan to continue development and even use the ultracapacitors in Tesla products.

When Tesla announced the acquisition of the San Diego-based ultracapacitor and battery company Maxwell for over $200 million, it was unclear if it was for the company’s main business, ultracapacitors, or for its new dry electrode technology for battery cells.

The latter seems more likely.

Hieu Duong, the lead scientist for Maxwell electrode technology, said that the product he worked on with Maxwell business development director Chad McDonald led to the acquisition by Tesla.

He wrote in a LinkedIn recommendation for McDonald:

“Chad and I worked together to define and specify the requirements for Maxwell Technologies’ technical products which led to the acquisition of Maxwell by Tesla. In my role as lead scientist, I found Chad’s marketing and business development leadership to be critical to our ultimate success. Chad and I forged a very close working relationship and friendship and I find his ability to grasp advanced technologies to be very impressive. His leadership in defining and simplifying the value proposition for our technology was central to our success. In addition, the relationships he forged and the trust he gained with the team at Tesla have been recognized as major factors to the decision to acquire Maxwell.”

While Tesla’s interest is clearly in the battery technology, by buying Maxwell, Tesla also acquired the company’s main business: ultracapacitors.

Chris Stewart, now the ‘Head of Maxwell Ultracapacitors at Tesla’, says that 225 people work on ultracapacitors at the company and the business is worth “~$100 million.”

Here’s his job description on LinkedIn:

“Full operational and P&L responsibility for Tesla’s ultracapacitor business, formerly MaxwellTechnologies, Inc. Leading an organization of 225 people to deliver profitability and cash flow from Maxwell’s ~$100M ultracapacitor business.”

Since the acquisition was made official in May, Tesla started integrating the ultracapacitor business.

Maxwell engineering manager Mark Sutherland wrote on LinkedIn:

“Since Maxwell was acquired by Tesla I have continued my role as both a program/project manager for an ultracapacitor module and also managing a team of engineers.”

Tesla CEO Elon Musk first moved to California in the 90s in order to do a PhD on ultracapacitors, but he quickly stopped to start an internet company.

The technology enables much faster charging and discharging than battery cells, but they don’t hold as much energy.

Tesla never ended up using them in its vehicles and instead focused on all-electric long-range vehicles using Li-ion battery cells.

Ironically, Maxwell’s ultracapacitors are primarily used in plug-in hybrid vehicles, a technology that Tesla refused to adopt in favor of all-electric vehicles.

Therefore, by acquiring Maxwell, Tesla is technically now supplying other automakers for their PHEV programs.

The ultracapacitor modules in those vehicles are primarily used to start the internal combustion engine of the plug-in hybrid while the vehicle is running on electric mode.

For example, Geely and Volvo are using the ultracapacitors in their vehicles.

It’s unclear what are Tesla’s plans for the ultracapacitor division going forward.

Electrek’s Take

This is interesting because it sort of confirms what we already suspected, which is that Tesla was mostly after Maxwell’s battery technology in the acquisition.

However, it leaves the question: what are they planning to do with the ultracapacitor business?

Maxwell already had contracts that Tesla will likely be obligated to fulfill over the next few years, which is why they started integrating the ultracapacitor operations, but what happens after that?

Does Tesla keep the business going and try to find other contracts? Ironically, it would result in them becoming a supplier for PHEV vehicles, a technology that Tesla saw as a compromise over all-electric powertrains.

There’s also been some speculation that Tesla could try to implement the technology in its own products.

Maxwell’s ultracapacitor modules are used in the transition from electric to gas-powered in PHEVs, but they are also used for supporting peak voltage demands on the vehicle electric network and there’s been speculation that a battery-ultracapacitor hybrid powertrain could offer some advantages.

I honestly don’t know where things are going on that front, but I find the subject interesting.

What do you think? Let us know in the comment section below.

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