Compact voltage converter

A compact voltage convertor built with parts from Home Depot.

Visiting friends and relatives can also be an opportunity to charge an electric vehicle. Whenever a dryer or RV outlet is not available, a voltage convertor can be used to charge an EV three times faster than using a standard household outlet. Although I have a Quick 220 voltage converter, which includes several important safety features, I want something much smaller that can be stashed under the seat for emergencies, but the safety concerns may be too great.

Always be safe

Any home-made voltage converter should only be used by individuals familiar with testing electrical wiring. Connecting this kind of device to improperly wired outlets will create an unsafe situation with a risk of electrical shock.

A demonstration of very dangerous Reverse Polarity Bootleg Ground (RPBG) outlets.

Identify appropriate receptacles

The two plugs on the voltage converter must be connected to circuits on each phase of the electrical service. Study the layout of the breaker panel to identify candidate circuits and associated receptacles. Use a non-contact voltage tester like Fluke VoltAlert to confirm each receptacle is wired correctly, then verify circuits are actually out-of-phase by using a voltage tester.

WARNING: Be especially careful not to create a tripping hazard with electrical extension cords; when the voltage converter is in use and one plug is still connected, the other unconnected plug will still be electrified.

The appropriate receptacle for a 240 volt 20 amps circuit is the NEMA 6–20.

Electric Vehicle Charging

The continuous load generated by EV charging should only be 80% the total capacity of the circuit. TurboCord will correctly advertise 16 amps when connected to a NEMA 6–20 receptacle. The electric vehicle supply equipment (EVSE) should be plugged in last, and unplugged first.

Electric vehicle charging equipment should only be used on properly wired receptacles.

Conclusion

Whenever possible, there is no better option than to hire an electrician to properly install a 20 to 50 amp circuit for EV charging. Although it’s possible to build a voltage converter, anyone considering it should just buy a Quick 220 which comes in 15 and 20 amp versions.

This video shows the 15 amp version, but Quick 220 is available in a 20 amp version.

Disclaimer: This information is provided for educational purposes, and is not intended to have you circumvent an electrician. The author of this article will not be held liable or responsible for any injury resulting from reading or misuse of the information contained in this article. If you feel you have a dangerous electrical condition, make sure to contact a qualified licensed electrician.