48-Volt Electrical Systems

electricityVOLTAGE is to electricity what PRESSURE is to water: the more you have of it the more OOMPH you get. That is why electrical power lines work at high voltage. They need to feed a lot of houses with a lot of electrical devices, all at once.

In the 1950s carmakers needed extra OOMPH of this sort to start the powerful high-compression engines being introduced, so they increased the voltage of their vehicles’ electrical systems from 6 to 12-volts.
Now voltages are going up again. This time to 48-volts!

zoom1One reason for this jump, is that cars are packed with more and more components, demanding more and more electrical power. A modern vehicle may have as many as 150 electric motors powering windows, wipers, seats and other conveniences that we take for granted.

But there is a second reason for the increase. Extra voltage lets engineers design cars in creative ways that boost engine output and efficiency. This can be used to make hybrids and employ a combination of electric motors and combustion engines to cut both fuel consumption and polluting emissions.

Necessity
The new 48-volt systems will be essential to tomorrow’s cars due to:
• All the components for autonomous driving — cameras, radar, lidar sensors, computers, etc.
• A greater array of drivetrain components, the oil and water pumps and more, will switch from mechanical to electrical
• An assortment of hybrid-drive parts that will propel the car under electric power
• More computing power that will improve vehicles’ connectivity, not just to the Internet…
but to other vehicles, buildings, traffic signals and other structures in the environment, as we become more connected

Electrical architecture is not just about getting the voltage to everything electrically powered, it’s also about the data speed. It’s about the computing power and how you lay out the electrical system. Today’s cars process data at about 65 megabits, or 15,000 pieces of data, per second. Tomorrow, it’s 1.5 gigabits, or 100,000 pieces of data, per second ..and that number will continue to grow.

By 2025, automakers must achieve a fleet average of 54.5 mpg. But credits for such things as environmentally friendly air conditioners and stop-start systems means that the actual fuel economy rating on the window sticker can be less than 54.5 mpg in nine years, and vehicles will still meet the government’s mandates.

This means that full-line automakers — General Motors, Ford, Fiat Chrysler Automobiles — that are heavily dependent on sales of pickups and SUVs have to improve their fuel economy by as much as 5 percent each year to meet the standard.

Cost
It’s estimated that adding 48-volt capability would only cost consumers around $1,200. And it’s no longer a question of waiting for the technology development. It’s ready and being used today. Most are test vehicles, but some are in production.

sq7Audi SQ7
The first production car to use 48 volts is the SQ7, a new luxury sports-utility vehicle made by Audi. It is not a hybrid, but it employs an electrically driven 48-volt turbine to force extra air into the engine when a burst of power is needed.

The car also has a 48-volt active suspension. Again, this improves response time, permitting faster action from the electric motors that control how the vehicle rolls on corners. All of these great new technologies add up to an efficient vehicle with exceptional handling.

adeptADEPT drive
The hybrid possibilities of high voltage are shown by an experimental Ford Focus being put through its paces by the Advanced Diesel-Electric Powertrain (ADEPT) consortium, in Britain. ADEPT, uses 48-volts to power components ranging from the water pump to an electric turbine.

ecodriveEco Drive
Continental has developed a 48-volt system that will be used in the Renault Scenic for Europe. The Scenic application uses what Continental calls Eco Drive, a stop/start system that operates on a 48V circuit instead of the vehicle’s main 12V electrical bus and is powered by a lithium-ion battery with capacity of about 0.5 kWh.

Fully Electric
So by now you are wondering about fully electric vehicles and the voltage that they are using. Well, for comparison – Tesla uses roughly 3-400 volts depending on the battery array size, as the “battery” is actually made up of over 7,000 batteries. A typical hybrid, like a Prius for instance, will use about 2-300-volts. But where the 48-volt will be very useful is in its compact size and the potential to be added to an existing vehicle.

quantWhich finally brings us to the nanoFlowcell. The QUANTiNO 48VOLT is another exciting advancement. QUANT is a company that is testing a fully electric vehicle that would run on a mere 48-volts!

Most carmakers and their suppliers are now working on 48-volt systems and mild hybrids could cut CO2 emissions by 15-20%.

It’s expected that, by 2025, one in every ten cars sold around the world will be a 48-volt mild hybrid.

Upping the volts, then, will make motoring much greener.

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