While this isn't the first time rechargeable tool batteries have been used to power an EV, these are some pretty special batteries. Pictured above is Drill Bike. The EVAlbum page is here and the website is here.
One of the interesting aspects of the Drill Bike build is that the batteries were not physically altered. The builder bought a bunch of rechargeable flashlights and sawed those up to provide a dock for each battery. Very cool!
The build is based on 36V batteries that were designed by A123 Systems for DeWALT. Apparently EV nuts aren't the only ones interested in these batteries. It turns out that the RC crowd is taking them apart for use in various radio controlled endeavors. For example, LBMiller5 took one apart here and shared the steps. Interestingly, each battery pack has its own integrated battery management system. That's pretty cool.
Will the EV550 use these batteries? I'm not sure yet - but I'll be scoping out these batteries pretty closely.