Friday, May 30, 2014

Shaft & Batteries




The shaft to connect the motor with the transmission is ready and looking very nice! I'm looking forward to get the setup spinning. But right now the motor and transmission are still at Klaus AG because the motor still needs to be mounted to the original mounting bracket. We have to find a good approach to replace the huge prototype made of wood with a construction made of aluminum. This is currently my biggest worry.
The battery construction is making great progress and I'm confident to get a working approach. I started to replace parts of the wooden construction with T-shaped aluminum struts and now I'm able to determine where and how many batteries can be placed. In the exhaust pipe tunnel 17 cells find their place, in the gas tank area at least 45, in the area of the spare tire 22-24. This leaves only about 36 cells which have to placed in the engine compartment. The huge trunk will remain untouched - and this with 120 cells of CALB CA 100Ah. Most of the cells are placed at the lowest possible point in the car - resulting in a low center of gravity. I will create a movie to illustrate how I did it.
Also the wiring diagram is 90% complete. My version of the GEVCU will support 1 relay to connect the pre-charge resistor with HV+, 1 contactor to connect HV-, one contactor for HV+ and only relay to switch the enable signal for the controller. The sequence is like listed before: first the pre-charge relay closes, no current is running yet and no sparks are created in the relay. Then the HV- contactor closes and the capacitors are pre-charged. The contactor is hermetically sealed and thus less prone to sparks. When the pre-charge cycle is completed, the HV+ contactor closes and then the pre-charge relay opens. The HV part is ready to operate and thus the "enable" relay is closed to signal the controller and DC-DC converter to start their operation.
Next steps: Finish battery construction and boxes and the motor mounting. Then I'll be able to connect the cables and get it moving. Timeline? Hopefully within the next 1-2 months.




Oh yeah, almost forgot: I made another small video about the day of electromobility here in Zurich and about the EFORCE - a conversion of a truck: