Tesla Kills 12-Volt Car Systems: Goes to 48-Volt but Will Industry Follow?

Today during the Tesla “Investor Day” it revealed that its cars will now have 48-volt electric systems. As we’re sure you’re aware, vehicles have used 12-volt electric systems since the 1950s. So why does there need to be 48-volt systems in cars, and will the auto industry, as a whole, switch over as well? 

Is Tesla the first to switch to 48-volt systems?

Tesla component breakdown | Tesla

We should start by saying Tesla isn’t the first automaker to flip the switch to 48 volts. Numerous automakers incorporate 48-volt systems within their mild-hybrid systems. For mild hybrids, 48-volt systems create more power without reducing fuel economy. But production juggernauts like Tesla breaking with 12-volts for their EVs means the entire industry is on notice. So what is it for, and why is Tesla doing it now?

Tesla’s moving to Li-ion 12-volt batteries was the first move back in 2021. But the energy in the batteries depletes fairly rapidly. Some of this is due to climate, and how far you drive between charges. That’s because just like a 12-volt alternator, the farther the car goes the more the battery recharges.

Why are 48-volt electric systems better?

New Tesla wiring system | Tesla

A 48-volt system lowers what’s called “resistive loss.” Cramming all of the energy through 12-volt systems means more resistance, so the system needs more electrical energy. Climate control, driver assist systems, and infotainment requirements mean they all need more electricity. So there is less energy loss, and electric components provide quicker results because there is more electric current.  

Right now, with 70 years of 12-volt systems in vehicle production, there has been little movement toward 48-volts. It was going to take a big automaker to make the switch before the industry transitioned into force. One reason for delinquency has to do with the components needed.

Are 48-volt components made now?

Tesla Model S | Tesla

Going to 48-volt means new components operating with more voltage need development and then manufacturing. There are some 24-volt system components available for marine, small prop planes, and truck applications, but not that many. And John Deere also uses 48-volt systems in their row-crop planters. 

Going to 48 also volts means wiring looms will also need to be different, to be able to carry higher voltage. But the wires used in a 48-volt system can be a smaller gauge, so they’re both lighter weight and cheaper. That’s another advantage.  

How soon will the industry follow Tesla?

Tesla electric motor system | Tesla

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Some EV makers may choose to go with both 12-volt and 48-volt in tandem according to Dalroad Components. The components performing better with one electric system work with that system. Tesla CEO Elon Musk has brought up transitioning to 48-volt systems for a few years. But now the switch is flipped. 

How long this takes and how it manifests itself remains to be seen. But as the economical and marketing advantages position some EV makers as more advanced than those who choose not to use 48-volt systems, the transition will speed up.