This is where it gets really interesting, as there are no formal guidelines or standards just for motorbikes. I have reviewed some of the information available online, and Phil at Nippon Performance has been in contact with QLD Transport to identify what is required for certification so that we can get the bike approved and registered.
QLD Transport acknowledged that there are no regulations or guides specific to motorcycles and have recommended following the National Guidelines where applicable for the installation of electric drives in motor vehicles.
For the latest version of the Guidelines search, (Vehicle Standards Bulletin 14 - National Guidelines for The Installation Of Electric Drives In Motor Vehicles.)
In this blog I will be referring to relevant sections of the Electrical Drive Guidelines.
Section 2.1 - Electrical Definitions
ELV: Extra Low Voltage refers to voltage not exceeding 60V DC.
HAZV: Hazardous Voltage refers to voltages that exceed 60V DC.
On the bike, we will have both an ELV 12-volt system for the bike and control circuits, and the HAZV 78-volt traction circuit that connects the batteries to the motor controller.
Section 2.2 - Battery Type
The batteries I will be using on the bike are Lithium Ion batteries which are Class A:
Section 2.3 - Battery Restraint
This section features the guidelines for how the batteries are protected from being dislodged and damaged. In our case, the batteries will be contained in an Aluminum Box; they will not be going anywhere.
Section 2.6 - 2.8 Refer to the labeling and use of warning labels on areas that contain high voltage. Access to HV connections must require a tool to remove covers.
HV Warning Label recommended;
Section - 2.9 Hazardous Voltage Isolation
Any HAZV battery system must be isolated from the chassis of the vehicle. In our case, this means that unlike the 12-volt system that is earthed to the bike frame, the 78-volt system will be isolated from the frame.
Section - 2.10 Hazardous Voltage Disconnect
The power-on procedure must be applied via a key switch. Disconnection of the batteries from the motor controller must be done via a contactor, and an inertia switch should be employed to disconnect the batteries from the circuit in the event of a collision.
The guidelines have a nice electrical drawing as an example of how this can be achieved. We will need to investigate the use of the inertia switch to disconnect the batteries, as this would blow the motor controller if the switch was to trip after hitting a bump in the road.
Section - 2.11 Hazardous Voltage Protection
This covers where and what types of fuses or overloads should be used.
Section - 2.12.1 Auxiliary ELV
An independent auxiliary ELV (12-volt) must be used to guarantee the supply of power to safety equipment such as the lights.
The auxiliary supply can be charged via a DC/DC converter.
For this project, we will be switching the power between the 78-volt battery pack and the motor controller via 2 x 500-amp DC Contactors, all controlled from the 12-volt system on the bike. The 12-volt battery will be maintained by a DC/DC converter charger while the bike is in use, just like the old alternator.
The startup sequence for the electric motor controller is as follows:
The ignition key switch will supply power to the control circuit.
The bike kill switch will engage Contactor 1 and allow power to flow to Contactor 2, which has a Pre-Charge resistor across the open terminals. Power flowing through the resistor will limit the current flow and charge the Motor Controller.
Pressing the start button will bring in latching Relay 1. This will activate Contactor 2, allowing full battery power to flow to the Motor Controller.
Next the Motor Controller Kill Switch can be switched on activating Relay 2, and the light on the Controller will illuminate.
Now the LCD Screen can be turned on at the control panel, then the bike is ready to run.
This is the current drawing I have drafted for the 12-volt control circuit to comply with the Electric Drive Guidelines.
To speed up the startup process, we can leave the bike's Kill Switch and Motor Controller Kill Switch turned on, then the startup is simplified.
Turn on the ignition Key Switch; power will flow through the Kill Switch, activating Contactor 1 and pre-charging the controller.
The start button will close Contactor 2 and start up the motor controller. Since the controller has already been charged, Relay 2 will be activated to start the controller.
Now the LCD screen can be activated, and the bike is ready to run.
You will notice I have added a couple of warning lights to the circuit. This will help me determine what state the bike is in.
If I forget to press the start button, the red battery light will illuminate. As the Inertia Switch doesn't have normally open and normally closed contacts, I have placed an Engine Fault LED indicator light across the switch so that if it opens circuits, the light will illuminate to indicate the Inertia Switch has tripped.
Next, we have the drawing for the 78-volt control circuit. This circuit also includes the 78-volt Battery Charger and a DC/DC Converter to charge the 12-volt battery on the bike.
Following on from the startup process, you can see that once Contactor 1 is closed, the Pre-Charge Resistor and DC/DC Converter are now activated.
Once Contactor 2 is closed, the motor controller will have full power.
I have added an isolation switch to the 78-volt charger. This may not be necessary as the charger can stay connected to the circuit, as long as it is off when the bike is turned on.
Now we can start wiring the 12-volt circuit on the bike and see how it operates.
