Ecotality said Thursday it bought Edison Minit-Charger, a company that makes charging systems for forklifts and other industrial electric vehicles, for $3 million.

The deal marks the fourth acquisition this year for Ecotality, a company involved in hydrogen and fuel-cell technologies.

But as the Scottsdale, Ariz.-based company touted plans to make even more acquisitions as part of its strategy to become a green-electricity rollup company, at least one industry watcher suggested the approach might turn off investors.

Ecotality said it expects to close its latest acquisition, a subsidiary of Edison International, within the next week and move the company, now based in Canada, to Arizona in the next three months.

The company claims the Minit-Charger system recharges batteries up to six times faster than conventional chargers, meaning vehicle operators can recharge batteries during a break, instead of changing out batteries for a recharge that traditionally can take six to eight hours.

Since its founding in 1998, Minit-Charger has sold $40 million in products, including revenue of $5.16 million in the 12-month period ending Sept. 30.

Frost & Sullivan projects the North American industrial fast-battery-charger market will grow 17 percent from this year and an average of 18.9 percent from 2006 to 2013.

Ecotality apparently finds the potential market alluring. In November, the company bought Electric Transport Engineering Corp., which makes chargers for electric cars and trucks such as airport ground-support and neighborhood vehicles, for $6.25 million (see Ecotality Buys eTec).

The company also bought Innergy, which makessolarpanels, solar-powered chargers and thin, rechargeable, lead-based batteries, and Fuel Cell Store, an online fuel-cell retailer, this year (see Ecotality Buys Innergy for $3M), spending a total of $13.75 million on all four acquisitions.

CEO Jonathan Read said acquisitions are key to the company's long-term goal of getting deeper into the electric-vehicle market.

"It is very much to move in lock step with (car manufacturers) and the introduction of the plug-in hybrids and all-electric vehicles," Read said.

Founded in 1999 as Alchemy Enterprises, Ecotality originally made biodegradable cleaning chemicals. Last year, a group of investors took control of the company, switching its focus and changing its name. 

Despite all the buyouts, Ecotality expects to be a revenue- and earning-positive company in 2008.

Not everyone believes the success of the electric-car market is a sure thing, however, as many technical and financial hurdles remain (see Honda Says No to Plug-In Hybrids, Khosla Calls Plug-in Cars 'Toys', Batteries Key to Plugging in at Electric Vehicle Symposium and Who's Reviving the Electric Car?).

Too Much of A Good Thing

One company snatching up so many others in one year has raised red flags for Michael Butler, CEO at investment bank Cascadia Capital.

"When growth strategy is really dependent on making acquisitions, that's less attractive to investors," Butler said, adding that integrating an acquired company's technology and people is challenging and brings additional risks.

He said it's more attractive when companies grow their own technologies in-house and then use select buyouts to supplement them.

He pointed to lithium-ion battery developer A123Systems, which bought plug-in hybrid company Hymotion in May.

"They have a real business, a real product, and the acquisition they made was to fill a void in the product," Butler said.

Conversely, he said, good companies in a rollup "aren't going to sell."

But Read defended his strategy, saying Ecotality has purposely sought out midlife companies that are ready for their next stage of growth and that could benefit from operating under a single renewable portfolio in order to bring about shareholder returns.

While it continues to spend money -- about $1.1 million last year, or 30 percent of its $3.6 million operating budget -- on its own research and development, the company has spent far more on its acquisitions.

And that trend is expected to continue. Read said Ecotality plans to continue its buying spree next year.