I'll be the first to admit: When I look at AeroVironment (NASDAQ:AVAV), I do so with blinders on.

To me, AV is first and foremost a defense contractor. A scrappy upstart maker of unmanned aerial vehicles (UAVs), dogfighting giants like Boeing (NYSE:BA), Lockheed (NYSE:LMT), and Northrop (NYSE:NOC) for a piece of the pie in unmanned-aerial supremacy in the sky. I rarely, if ever, consider whether AV's roof-mounted mini-windmills mount a serious challenge to Exxon Mobil's petro-empire, or even to fellow energy revolutionaries like First Solar (NASDAQ:FSLR).

And then there's AV's third field of endeavor: fast-charging reusable batteries. I've always suspected that this "PosiCharge" division could play a role in making GM's (NYSE:GM) new Volt electric car user-friendly. But until we see Volts taking up space at GM dealerships, that's more speculation than fact. While it's been one of the cornerstones of AV's evolution into its current form, the PosiCharge division has dwindled in significance to the company. It sports the worst gross margins of any of AV's three divisions (around 29%), and its share of companywide revenue has fallen from 14% to 9% over the past three years. Basically, I've written off "PosiCharge" as a technological curiosity, but little more.

Surprise!
Which shows you how much I know. AV issued a press release yesterday that appears to have serious potential to change the company's revenue make-up. According to the press release: "Toyota (NYSE:TM) Material Handling, U.S.A. ... the number one lift truck supplier in the United States, and AeroVironment ... have established an alliance to market AV's PosiCharge fast charge systems ... through 68 authorized Toyota Industrial Equipment dealers with 190 locations throughout the United States."

How big a deal is this? I'd love to tell you, but it's hard to come up with an accurate figure. I do know that Toyota is the largest manufacturer of lift trucks (more commonly known as forklifts) in the U.S. It sold $5.5 billion worth of the contraptions in 2006, whereas PosiCharge booked less than $20 million in revenue that year.

Hypothetically, if PosiCharge can piggyback on this giant enough to make its product constitute just 1% of the cost of the lift trucks Toyota sells, this could almost triple AV's annual PosiCharge sales. A 3% sliver would just about equal AV's current sales-leading division, UAVs. And 4% would make AV a battery-charging company with a defense-contracting sideline.

So I repeat, how big a deal is this? I don't know, but I have a hunch it could be huge.

For more on what we do know about AV, read:

Fool contributor Rich Smith owns shares of AeroVironment and Boeing. At The Motley Fool, we have a disclosure policy.