DeWALT Batteries for an EV

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.

ReVolt!

If you haven't already seen it, there is a sweet open source DC controller project in the works by the name of ReVolt (I dig the name).

The controller is one of the more expensive bits of an EV. It looks like building this yourself would save gobs of money (a good thing).

The project is still getting off the ground, but a few prototypes have been put together and it looks like it's working well. I'm excited because this hits on all the cylinders of my interest in building EV's:

• It's DIY so I have the pride of building it and I know how to fix it if it goes wrong
• It's cheap
• Did I mention it's cheap?

The designer of the unit is trying to get some kits together to make it easier for non electronics pros (e.g. me) put together a unit pretty easily.

Once I get the bike to a rolling chassis, I plan on putting one of these together. The idea is that I'll testbed the controller in the bike and either re-use or make another one for my eventual car conversion.

Head on over to Paul and Sabrina's EV Stuff for more information on the controller and some videos of their conversion in motion.

In Wheel Motors

I'm still coming up to speed on the history of the electric car (I'm watching Who Killed the Electric Car as I type). One of the more interesting approaches to EV design utilizes in-wheel motors. By putting the motor in the wheel, you get rid of heavy items such as transmissions, axles etc. This leaves more room for people, crumple zones, batteries / fuel cells, etc.

Here is a run down of the in-wheel motors that I've encountered so far. The commonality between each of these units is that none of them are available to the general public. Are there any in-wheel motors available to buy off the shelf today?

Michelin Active Wheel
The in-wheel electric motor is nothing new, but it's nice to see some additional manufacturers jumping on board. It looks like Michelin (yes, the tire company) is testing their own version. This unit includes both the motor as well as active suspension components.

By putting the motor and suspension components in the wheel, this reduces the amount of unsprung weight in a car.




Source: Zoomi Life

Hi-Pa Drive from PML flightlink.
This company / unit appears to be in startup mode. Their flagship prototype is an EV F-150 pickup that has an in-wheel motor in each corner.



Siemens eCorner
This uses a "brake by wire approach". At first blush, electric braking scares me (risk of failure, etc), but I guess I should look more into it before I dismiss it.