This post explains how ONYX riders interact with public J1772 EV charging stations, why stock ONYX chargers cannot take full advantage of 240-volt Level 2 power, and what would be required to safely enable true 208–240 V charging.
- Always set the 120V / 240V mode switch on the ONYX 80V charger to the 220V position when using a J1772 adapter at an EV charging station. Failing to do so can damage the charger.
- Switch the 120V / 240V mode back to the 110V position before plugging the charger into a standard household 120-volt outlet.
What This Explains and Why It Matters
For many ONYX 80V riders, this bike is their first electric vehicle and their first exposure to public EV charging stations. That means a lot of assumptions from household outlets do not carry over, and misunderstanding them can create real safety risks.
This explanation walks through:
- how household outlets and EV chargers move power differently
- why adapters do not magically create 240 volts
- what the ONYX charger is actually doing in the real world
- and what would be required to safely enable true 240-volt charging
The goal is not theory. The goal is knowing what is safe to plug in and why.
J1772 to Nema 5-15 or 5-20 Adapter
A J1772 to NEMA 5-15 or 5-20 adapter is a passive adapter that lets you plug a device with a standard household plug into a J1772 EV charging station, but it only provides 110 to 120 volts, not true 240 volts, because it uses a single hot and neutral just like a normal wall outlet.
A voltage socket checker is a simple safety tool that plugs into an outlet to detect the presence of voltage and common wiring faults such as reversed hot and neutral, missing ground, or incorrect voltage before anything else is plugged in.
J1772 Connector
For a NEMA 5-15 or 5-20 to carry 240 volts, one hot leg would have to be connected to the hot blade (AC Line 1) and the other hot leg (AC Line 2) would have to be connected to the neutral blade. That eliminates a true neutral return path and places line voltage on a conductor that is not intended for it. This can force fault current onto the ground path, energize metal components, and defeat the safety function of both the neutral and the ground.
If neutral and ground were treated as interchangeable, normal return current could flow through safety paths. That can energize a charger’s metal enclosure, the bike frame, and the battery case. It can also interfere with proper BMS fault detection and cause GFCI protection to nuisance trip or fail to trip when it matters. Neutral is a current carrying conductor. Ground is a protective one. J1772 includes a ground but no neutral by design. That is why a NEMA 5 15 can never substitute for a true 240 volt EV connector.
- A 120-volt NEMA 5-15 or 5-20 requires a neutral because it operates on a hot-to-neutral circuit.
- In a 240-volt J1772 circuit, power flows between two hot conductors. As the AC waveform alternates, each hot takes turns serving as the return path.
- J1772 includes Control Pilot and Proximity Pilot lines that handle communication and safety interlock functions.
| Connector | Hot | Ground | Ground |
|---|---|---|---|
| NEMA 5-15/20 | Yes | Yes | Yes |
| J1772 | Yes | No | Yes |
How a Normal Wall Outlet Actually Works
A standard NEMA 5-15 or 5-20 outlet is a 120-volt system. It is designed around a very specific idea:
- One wire sends power out
- One wire brings power back
That return wire is called neutral.
Neutral is not a backup. It is part of the normal operating circuit. It carries current every time the device is running. The third pin, ground, is different. Ground is only there to protect you if something fails. Under normal conditions, ground should carry no current at all.
This separation is intentional. It keeps metal parts safe to touch and makes faults predictable.
Why You Cannot Turn a 5-15 or 5-20 into 240 Volts
To force 240 volts onto a NEMA 5-15 or 5-20 outlet, something unsafe would have to happen.
One hot wire would be connected to the hot blade. The second hot wire would have to be connected to the neutral blade.
At that moment:
- the outlet no longer has a true neutral
- a wire meant to safely return current is now carrying live voltage
- the outlet is lying about what it is
This breaks the safety model the outlet was designed around.
When that happens:
- fault current can be pushed onto the ground path
- metal parts can become energized
- safety systems behave unpredictably
If neutral and ground were treated as interchangeable, normal operating current could flow through paths meant only for emergencies. That can energize a charger’s metal enclosure, the bike frame, and the battery case. It can also interfere with BMS fault detection and cause GFCI protection to nuisance trip or, worse, fail to trip when it matters.
Neutral carries current. Ground protects you.
They are not interchangeable, and treating them as such is exactly why this configuration is unsafe.
This is why a NEMA 5-15 or 5-20 can never substitute for a true 240-volt EV connector.
Why J1772 Works Differently
J1772 was designed from the start for higher voltage charging, so it follows a different model.
A 240-volt J1772 system does not use neutral at all.
Instead:
- it uses two hot wires
- power flows between them
- as AC alternates, each hot takes turns carrying current
Because of that design:
- no neutral is required
- a dedicated ground is still present for safety
- current stays predictable and controlled
J1772 also includes Control Pilot and Proximity Pilot lines. These handle communication, current limits, and safety interlocks. They are one of the reasons EV charging can safely deliver high power without guesswork.
What Public J1772 Stations Actually Provide
Most public charging stations used by ONYX riders are J1772 Level 2 stations, commonly rated around 6.24 kW. That typically means 30 amps at 208 to 240 volts.
These stations are built to supply true 240-volt power to vehicles and chargers designed to accept it.
Why Stock ONYX Charging Is Limited to 120 Volts
ONYX riders often connect to these stations using J1772 to NEMA 5-15 or 5-20 adapters. While this allows a physical connection, it does not change how power is delivered.
NEMA 5-series connectors are hot to neutral. That means:
- only 110 to 120 volts are exposed
- the second hot from the station is not used
The stock ONYX 80V charger uses a NEMA 5-15 input, so there is no true 220 to 240-volt charging path in stock form. This remains true even when the charger is set to 220V mode.
The connector itself is the limiting factor.
What You Actually See When Charging
Because the charger is still receiving 120 volts, the ONYX 80V 10-amp charger continues to draw about 8 to 10 amps from the wall. It does not drop to 4 to 5 amps unless it is truly connected to a 240-volt source using a connector designed for that voltage.
The voltage selector switch does not control current on its own. Lower current only happens when:
- a real 208 to 240-volt source is present
- the input connector supports that type of power
Without both, the behavior does not change.
Load and Safety in the Real World
Running two ONYX 80V 10-amp chargers on a single J1772 to 5-15 or 5-20 adapter can pull 16 to 20 amps continuously at 120 volts. That exceeds safe limits for sustained use.
The same concern applies to higher-power aftermarket chargers. A 20-amp charger is unsafe on a 5-15 adapter and only acceptable on a 5-20 adapter if current is limited to 16 amps or less.
This is where most real-world problems happen. The outlet may not fail immediately, but heat builds quietly over time.
What the 120V / 240V Switch Actually Does
The 120V / 240V switch is not a speed switch. It does not convert voltage and it does not override the connector.
Its job is to prepare the charger’s internal power supply for the voltage it expects to see by adjusting protections such as:
- input filtering
- inrush current limiting
- voltage stress tolerances
It tells the electronics what range to expect so components stay within their safe operating limits. That is all.
What Would Enable True 240-Volt Charging
If the ONYX 80V charger’s NEMA 5-15 input were physically replaced with a NEMA 6-20 input, and the charger were set to 240V mode, it could finally accept true 208 to 240 volts.
In that configuration:
- input current would drop roughly in half
- about 4 to 5 amps would be drawn for the same 10 DC amps delivered to the battery
- heat and stress on wiring would be reduced
The charger would operate hot to hot instead of hot to neutral, eliminating the need for a neutral and matching how J1772 stations are designed to work. Continuous operation would be safer and compatibility with EV infrastructure would improve.
Final Constraint and Safety Rule
Without physically changing the connector to a true 240-volt type, the charger cannot receive real 240 volts, regardless of switch position.
The switch prepares the charger. The connector and wiring decide what voltage is actually delivered.
That physical reality is what keeps people safe.