48-volt electrical system

DC electrical system used in cars

A 48-volt DC electrical system voltage is a relatively low-voltage electrical system that is increasingly used in vehicles. It began in the 2010s as a way to increase the propulsion and battery recharge during braking for fuel savings in internal combustion engine vehicles, especially mild hybrid vehicles.[1]

## History

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Traditionally, vehicle low-voltage applications were powered by a 12-volt system. In the 1990s, an attempt by a cross-industry standards group to specify a 42-volt electrical system failed to catch on and was abandoned by 2009.[2] During the 2010s, renewed interest arose for a 48-volt low-voltage standard for powering automotive electronics, especially in hybrid vehicles.[3]

In 2011, German car manufacturers Audi, BMW, Daimler Benz, Porsche, and Volkswagen[4] agreed on a 48 V system[clarification needed] supplementing the legacy 12 V low-voltage automotive standard.[5]

In model year 2017, the Renault Scenic dCi Hybrid Assist was the first 48 V mild-hybrid passenger car.[citation needed]

As of 2018, a 48 V electrical subsystem operated production vehicles such as Porsche and Bentley SUVs. Audi and Mercedes-Benz used a 48 V subsystem in 2018 vehicles such as A6, A7, A8 with 3.0 TDI 48 V mild-hybrid, CLS, E-Class, S-Class with M256 3.0 Turbo Otto 48 V Mild-Hybrid.[6][clarification needed]

Hyundai Tucson, Hyundai Santa Fe, Kia Ceed and Kia Sportage followed in model year 2019 with 1.6 and 2.0 turbodiesel engines supported by 48 V mild-hybrid technology.[citation needed]

A European automotive trade association, CLEPA, estimated in 2018 that as many as 1 of every 10 new vehicles in 2025 would use at least one 48-volt device in the vehicle, covering 15 million vehicles per year.[7]

In March 2023, Tesla Inc. revealed that the Tesla Cybertruck and next-generation vehicle would utilize a 48-volt mid-voltage subsystem as a replacement of 12 V system, migrating the low-voltage components with highest power demand to 48 V.[8][better source needed]

In December 2023, in order to accelerate the adoption by other automakers of 48 V system voltage for automotive components, Tesla offered a "48-volt electrical system whitepaper" to all industry leaders. CEO Jim Farley confirmed that Ford had received a copy and agreed to 'help the supply base move into the 48-volt future".[9] Tesla also adopted 48 volts for its Optimus robot.[9]

## Benefits

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A 48 V system can provide more power, improve energy recuperation,[7] and allow up to an 85% decrease in cable mass.[10]

12-volt systems can provide only 3.5 kilowatts, while a 48 V power could achieve 15 to 20 kW or even 50 kW. 48 volts is low enough to be considered safe in dry conditions without special protective measures.[11] (See the article on electrical injury.)

One example of where these benefits can be used is in the Gordan Murray Automotive T.50, where it uses an integrated starter-generator to generate power for a 48 V AC compressor, without the need for a belt. This allows the engine to rev more freely and give the vehicle good AC, no matter the RPM.[12]

Another example is with the use of electric turbochargers, active suspension, and rear-wheel steering systems that require a lot of power to run, and might be more responsive and capable with a 48 V system.[13]

## See also

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* Automotive battery
* Extra-low voltage
* Load dump
* List of electric vehicle battery manufacturers

## References

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1. ^ Tracy, David (January 13, 2017). "Everything You Need To Know About The Upcoming 48-Volt Electrical Revolution In Cars". Jalopnik.
2. ^ Allen, Mike (1 October 2009). "Whatever Happened to the 42-Volt Car?". Popular Mechanics. Retrieved 15 December 2023.
3. ^ Why Cars Are Moving to 48-Volt Electrical Systems, Bill Howard April 26, 2017 https://www.extremetech.com/cars/247889-cars-moving-48-volt-electrical-systems
4. ^ Vollmer, Alfred (June 14, 2011). "Deutsche OEMs setzen Standards". all-electronics (in German).
5. ^ Hammerschmidt, Christoph (June 16, 2011). "German carmakers agree on 48V on-board supply, charging plug". eeNews Automotive.
6. ^ Mayersohn, Norman (February 8, 2018). "To Power the Future, Carmakers Flip on 48-Volt Systems". The New York Times (subscription required).(subscription+required)Category:Pages+containing+links+to+subscription-only+content&rft.atitle=To+Power+the+Future,+Carmakers+Flip+on+48-Volt+Systems&rft.date=2018-02-08&rft.aulast=Mayersohn&rft.aufirst=Norman&rft_id=https://www.nytimes.com/2018/02/08/business/electric-cars-48-volts.html&rfr_id=info:sid/en.wikipedia.org:48-volt+electrical+system" class="Z3988">
7. ^ a b 48 VOLT: A proven technology to reduce CO2 and NOx emission, CLEPA, 2018 https://clepa.eu/wp-content/uploads/2018/01/CLEPA-48v-technology.pdf
8. ^ Schulz, Bailey (November 30, 2023). "What we learned from the Tesla Cybertruck delivery event about price, range and more". eu.usatoday.com. Retrieved December 7, 2023.
9. ^ a b "5 Tesla Cybertruck Features That Didn't Make It Into Production and Five No One Saw Coming". AutoEvolution. 10 December 2023. Retrieved 18 December 2023.
10. ^ 48-V Systems: What You Need to Know as Automakers Say Goodbye to 12 V, 21 July 2023, Today, 48-V power systems are already helping improve the efficiency and performance of ICE and mild hybrid vehicles, but they will become an essential technology for tomorrow's EVs, Lee Goldberg, Related To: Electronic Design https://www.electronicdesign.com/markets/automotive/article/21269271/electronic-design-48v-systems-what-you-need-to-know-as-automakers-say-goodbye-to-12-v
11. ^ Texas Instruments Bullish on 48-Volt Automotive Systems, Dan Carney, March 31, 2021 https://www.designnews.com/electronics/texas-instruments-bullish-on-48-volt-automotive-systems
12. ^ "The Gordon Murray Automotive T.50 Is the 654-HP, 2174-Pound Successor to the F1". Road & Track. 2020-08-04. Retrieved 2024-08-09.
13. ^ "What Is a 48-Volt Mild-Hybrid System?". Capital One Auto Navigator. Retrieved 2024-08-09.

* 48 V Vehicle Electrical System – More Than Just a Bridging Technology? Dusan Graovac, Christoph Schulz-Linkholt, Thomas Blasius, 23 April 2020, EE Times/Asia.(subscription required)
* ISO 21780:2020(en) Road vehicles — Supply voltage of 48 V — Electrical requirements and tests[clarification needed]