Sunday, April 25, 2010

Earth Day

I spent Earth Day at the local Community College displaying El Gixxer along with some other EV's.  Although I'm not a terribly social person, it was cool to hang out with the other local EVer's. When we weren't answering questions from the casual observer, we were busy comparing notes on our projects.
This video doesn't have much of the EV's in it, but I neglected to take any pictures (doh!), so I can only blame myself.
Earth Day Video

The Earth Day experience has inspired met get this thing road-worthy.  I need to start securing the batteries in the racks so they don't shift around. First on the list is a Guard for the left side of the Upper Battery Tray - to keep the batteries from falling out. 

The removable Guard is necessary for battery maintenance.  A simple piece made from 3/16 sheet aluminum, and of course cut with the plasma cutter.  The Guard mimics the geometry of the tray, but extends the left side of the tray high enough to prevent shifting of the power pack.

Sunday, April 4, 2010

Performance Corrections & Wiring Cleanup

I was so enamored by the fact that my creation actually worked, it completely escaped me that it wasn't working as planned.  The acceleration and range were on par with a toy.  I initially suspected the batteries weren't capable of generating the amps needed.  A quick visit to the B-B Battery site shows these 17AH units can do 299A for up to 5 seconds.  Pack voltage seemed plenty high after charging:  78.2V

I knew that any one of the components with temporary connections could be suspect.  First on the list to correct was the main battery disconnect.  Gone is the 30A breaker zip-tied to the wiring panel.  In its place is a real battery disconnect switch, mounted in a new aluminum bracket behind the battery tray.  Since I don't need access to the wiring panel to flip the power on, I could now ride with the tank on.
I also needed to mount the 400A  fuse, rather than suspend it off the contactor terminal.  I know there are mounting blocks for these fuses, but why not take advantage of the acrylic wiring panel, and save myself $20.  Looks cooler too.
Subsequent test rides still showed something not quite right.  Three trips down the street and back later, the bike would barely limp up the driveway, but the pack voltage was still 74V.  The best thing I could think of was to pull some data from the controller while riding.  This would also give me a chance to tweak the controller settings.  Upon connecting the controller to the software, my neglect was evident.  The "Under Voltage" slider was was maxxed out, essentially cripling the controller immediately.  By hitting the "Defaults" button, reasonable starting values were inserted, but I upped the top speed and Max Output Curent a little just to be safe.
Acceleration is much better and the controller logs show almost 180A.  I will need to get some lights wired up ASAP so I can test the range.

Starting to feel like a real motorycyle.