Saturday, March 1, 2014

Battery Pack Containment System 3D Model

Now I have just burned about 30 hours of my life to design a battery containment system for the 24 LiFePO4 cells that will power it. Here is the 3D model:

It will bolt in on the same mounts that used to attach the engine. This will be laser cut and tab together with a little bit of TIG welding. The transparent end caps are polycarbonate. The rest of the structure will be aluminum. I should have the parts back in hand in about 2 weeks to TIG together.

Tuesday, February 18, 2014

No Load Speed

Last night I was able to finally measure speed of the rear wheel with a laser tach. I got 1194 rpm which equates to 85 mph. My targeted speed range is 60-70 mph. It will be interesting to see what I really get with the significant aerodynamic loading.

Sunday, February 16, 2014

E-Bomb Comes Alive! Electric Motorcycle First Run

Yesterday I was finally able to get the controller programmed. I used the Alltrax software and had no problems whatsoever. It was very simple to use. I then spent most of the day wiring with 4 gauge cable. I custom built all the wires because I could not buy the right lengths. I crimped all the ends and then soldered them for a really low resistance connection.
It actually runs pretty good and the speed looks pretty good. Check out the video

I am planning to get a laser tach and calculate speed in the next several days. I was targeting 60-70mph. I think maybe we are seeing a it more than that at no load. I will measure and see. Now I just need to package the batteries and attach to the bike and we are ready to rip.

Saturday, February 15, 2014

Connecting Up The Batteries For The First Time

Last weekend I connected up the batteries all in series and measured voltage at 80 volts (24 LiFePO4 Cells).
I then put then on the charger for the first time and that brought them up to 86 volts in about 15 minutes. I then connected the high voltage battery pack to my DC-DC down converter that provides 12VDC and connected it to all of my low voltage electronics. That all worked well with no mishaps. Notice the rubber gloves just in case I do something stupid. 90 VDC will shock and it hurts.

The goal today is to program the controller (offline from the bike) and then re-install it, run all of the 4 gauge cable (custom build) and if time permits attempt to run the motor through the controller on full voltage on jack stands.

Saturday, January 18, 2014

LiFePO4 Battery Conditioning and Prep

The plan is to connect the cells in parallel and let them equalize and balance. I also measured the cell voltages and then averaged and that is exactly the voltage I get when I have connected the cells in parallel. It turns out it is 3.344 volts. Once they have had some time to equalize, I will put them in a big serial chain and then charge them all and ultimately connect them to the controller and run the bike on jack stands. 
That's 24 batteries.
I link all of these batteries today so they start out balanced at the same voltage. I am not currently running a BMS so it is extra important that I start out with balanced cells.