Cybertruck 48V Electrical Architecture
Tesla Inc. is known for its innovative design and for edge-cutting technologies used in its vehicles. Tesla is again in trend after the start of delivery of its Cybertruck. With its boldly unconventional bulletproof look, Cybertruck gives a unique and futuristic appeal to onlookers. It gives a range of 340 miles, can tow 11,000 pounds of weight, and accelerates 0 to 60 miles in just 2.6 seconds. Cybertruck has many unique constructional features like steer-by-wire, range-extender, rear-wheel steering, and unconventional 48V wiring architecture (harness).
In vehicles apart from the main power supply (400V or 800V) to motor, a small power is required to run the auxiliary units which include infotainment system, headlight and indicators, wiper, and to operate window glass and many other ECUs. Conventionally, 12V is used to power these auxiliary units in the vehicles but Tesla has used a 48V wiring harness and it is probably the first time in automotive history.
A separate set of wires(for power and communication) is required for each component(infotainment, lights, other sensors/slave) of the vehicle to its controlling unit (ECU/VCU/master). And if these wire harnesses are opened can extend to kilometers. But Tesla has 48V, ethernet, and CAN bus on the same cable to connect all the components in daisy-chain. Cybertruck still has some 12V components installed which get power from a 48V supply using DC-DC converters. Cybertruck is using steer-by-wire which uses motors to actuate the sensor signal to turn wheels. So, it is a very wise and bold decision (as a new supply chain mechanism needs to be developed) completely to switch to 48V.
Advantages of 48V architecture:
- Using 48V architecture has helped Tesla to reduce the wiring by 77% and copper requirement by 50%. This is supported by simple Ohm’s Law (V=I*R) and Power equation (P=I2*R). If voltage is less then more current is required to meet power requirement. And if current is increased then more thicker wire is required to carry current. So it is wiser to increase the voltage of the harness.
- Also if current is reduced the heating effect in the harness is reduced as heat generated = I2*R*T which increases the lifespan and safety of wiring harnesses.
(Note: V=voltage, I= current flow, R= resistance offered, and T = time)