All These Promised EV Swaps Need High Voltage Inverters. Automakers, Step Up

Selling an electric “crate motor” without an inverter is a joke.

byPeter Holderith|
Electric Vehicles photo

We read about cars getting EV swapped more and more these days. An offending combustion engine is removed, batteries and electric motors go in, and choking the carb on a cold day is a thing of the past. Whether or not you're on board with an electric drivetrain effectively wearing a vintage car as a costume, you probably know that EV swaps are expensive, and there's a good reason for that. It's not really an issue of batteries anymore; those can be sorted out for a reasonable price. It's not the motors or drive units either, because they're also relatively easy to come by. The real challenge is finding an inverter, and it's something automakers are completely dropping the ball on.

Inverters are absolutely necessary for all modern EVs to work. Effectively the motor's programmable brain, they turn direct current from the battery into the three-phase alternating current that electric motors crave. The problem is that if you want to do a swap, there aren't many aftermarket options to choose from. Think of it like switching from carburetors to electronic fuel injection—except there's no Holley, MSD, or any number of aftermarket companies making bolt-on kits. You're only real option is to work with what an automaker gives you, or spend about $5,000 on something from Cascadia Motion, which is effectively the only shop in town.

The 400-volt Cascadia Motion CM200, which typically costs around $5,000. Cascadia Motion

That price isn't reasonable. An automaker needs to step in and start selling easily programmable high-voltage (and perhaps low-voltage) inverters to the public for a reasonable price. Listen, no one else besides OEMs and automotive suppliers are really making these things. They're the ones that have the knowledge and the capability. If one stepped up to the plate, they could easily be a hero to the aftermarket for decades. The time to build these things for enthusiasts is now.

Gap in the Market

The frustrating part about this is that the world of hobbyist electric vehicles already has this all figured out. Lower power inverters are widely available long for stuff like go-karts and dirt bikes in the neighborhood of $100-$200. The issue is that they aren't really suitable for cars. The electrical components that are capable of turning DC power into an AC waveform, MOSFETs, get expensive above 100 volts, and therefore most of these hobbyist units top out around 84V, with currents typically below 500 amps. A little math reveals the limitations of a single-motor electric drivetrain using one of these cheap controllers: about 42kW (56 horsepower) in what would likely be a brief burst. The automotive enthusiasts among you will know that's not very much for your average motor vehicle.

My cheap electric go-kart uses a low-voltage inverter that can be bought for around $100. Peter Holderith

High voltages must be had if you want a reasonably powerful electric car. At least 100V, probably more like 200V-300V unless you want to get motor-melting current involved. Once you start to look for inverters in this voltage range, though, the only names you really see are automakers and automotive suppliers. As previously mentioned, Cascadia is the only real plug-and-play option if you're not using a car company's complete ecosystem of parts, and its prices are steep.

The result is that cheap and easy EV swaps aren't really possible right now, and automakers claiming to sell "EV crate motors" are mostly full of it. Ford's $4,340 "Eluminator" Mach-E electric motor doesn't come with an inverter. It's tough to make a comparison here, but that's like Ford Performance selling a V8 as nothing but a block, pistons, and a crankshaft. When you ask for everything else that Ford bolts on when it puts a 5.0-liter Coyote into a Mustang, the company says it won't sell it to you. Like, is that serious? That "crate motor" is literally a 205-pound boat anchor without an inverter. It's useless!

Ford's inverter-less Eluminator crate motor might as well be filled with confetti as the automaker currently sells it. Ford

Be a Hero

There's a whole universe of EV parts that an OEM could build for the aftermarket. Even something like a high-current battery management system would be nice, but inverters are necessary, and almost nobody is building high-voltage units for purchase.

Sure, I get it. The EV market is still growing and all the inverters automakers can build—or buy—they're putting into cars. But that's a narrow view of what's going on in the world of personal transportation right now.

Car companies are desperate for any way to differentiate their electric vehicles from the competition. The fact of the matter is, if your EV has a permanent-magnet synchronous motor (almost all of them do), it puts down its power exactly the same as pretty much every other electric car out there. It's like every jellybean-shaped crossover suddenly got the same 2.0-liter four-cylinder engine, and nobody can make theirs feel, sound, or perform any better. How do you build a unique brand like that? You can go after lovers of technology and people who think whoopie cushion seats are the funniest thing since Rodney Dangerfield got married, but what happens when everyone else catches up with their own gimmicks?

The answer is getting enthusiasts involved. That means supporting people building their own projects who are working with both high and low voltages. If a kid's electric go-kart has an inverter that says "Chevy" on the side of it, what do you think their first car is gonna look like? If someone decides to buy a used drive unit to EV swap their classic car and Volkswagen makes a great inverter, that's going to change their opinion of the brand.

Many automakers already build them in-house, there's a big gap in the market, and the potential to attract a loyal following is enormous. It's time for car companies to start taking this stuff seriously.

Email the author at

Car TechCultureElectric Vehicles