EV ChargersLevel 2
Wolfbox E40 EV Charger Manual
Setup, everyday use, maintenance and troubleshooting for the 40 A Level 2 EV charger, with verified specifications.
- Max power9.6 kW
- Max current40 A at 240 V
- Cable length25 ft
- NetworkedYes (Wi-Fi/Ethernet)
About the Wolfbox E40
The Wolfbox E40 is a 40 A Level 2 EV charger (electric vehicle supply equipment, or EVSE) certified under the ENERGY STAR program. It delivers up to 40 A at 240 V, a maximum of 9.6 kW.
At full output that adds roughly 29–38 miles of driving range per hour of charging, assuming a typical EV efficiency of 3–4 miles per kWh. The vehicle's onboard charger sets the real limit: a car that accepts less AC power than the charger can supply will charge at its own maximum rate.
It is network capable over Wi-Fi/Ethernet. Equipment includes an RFID card reader, a credit card reader, and a high-resolution display.
With no vehicle connected it draws 3.7 W of standby power. That standby figure is lower than 49% of the 430 Level 2 models in our database.
Specifications
| Brand | Wolfbox |
|---|---|
| Model number | E40 |
| Charging level | Level 2 |
| Maximum output power | 9.60 kW |
| Maximum output current | 40 A |
| Input voltage | 240 V |
| Minimum circuit rating at full current (125%) | 50 A |
| Charging outputs (ports) | 1 |
| Output cable length | 25 ft |
| Output cable gauge | 9 AWG |
| Network capable | Yes |
| Network connection | Wi-Fi/Ethernet |
| Demand-response (connected) capable | No |
| RFID reader | Yes |
| Credit card reader | Yes |
| High-resolution display | Yes |
| Revenue-grade meter | No |
| ISO 15118 (PLC) communication | No |
| Standby power, no vehicle connected | 3.70 W |
| Partial-on mode power | 4.68 W |
| Idle mode power (vehicle connected, not charging) | 8.52 W |
| Losses at full charging current | 10.6 W |
Safety information
- Have a licensed electrician install any hardwired charger and any new circuit or receptacle for EV charging. Most jurisdictions require an electrical permit and inspection.
- EV charging equipment must be installed in accordance with the National Electrical Code (NEC Article 625) or the Canadian Electrical Code and local amendments. EV charging is a continuous load, so the branch circuit must be rated for at least 125% of the charger's maximum current.
- Never use an extension cord, plug adapter or multi-outlet strip with an EV charger, and do not plug a portable charger into a worn or loose receptacle — these are leading causes of overheating and fires.
- Do not use the charger if the cable, connector or enclosure is cracked, crushed or shows exposed conductors. Take it out of service and contact the manufacturer or an electrician.
- Keep the connector in its holster when not in use and route the cable so it cannot be driven over or become a tripping hazard.
- Do not open the charger enclosure; there are no user-serviceable parts inside and dangerous voltages may be present even when it is not charging.
Installation and first-time setup
This charger delivers up to 40 A at 240 V. Because EV charging is a continuous load, a circuit that supplies it at full output must be rated at least 50 A — 125% of 40 A, rounded up to the next standard breaker size. Your electrician will size the conductors for that rating, the installed conductor type and the length of the run.
At 40 A the charger can be supplied by a 50 A circuit. Some models are offered in plug-in versions (typically NEMA 14-50 or 6-50) as well as hardwired versions; check which version you have. A hardwired connection avoids receptacle wear and is often preferred outdoors.
- Check panel capacity
Have the electrician perform a load calculation to confirm the service and panel can carry another 50 A circuit. If capacity is tight, ask whether the charger can be set to a lower maximum current or whether a load-management device is suitable.
- Choose the location
Mount the unit where the cable reaches the vehicle's charge port without stretching — this model's cable is 25 ft long. Allow for the side of the car the port is on and for parking either nose-in or tail-in.
- Pull the permit
The electrician obtains the electrical permit. Some utilities also offer rebates or special EV rates that require registering the charger.
- Install the circuit and mount the unit
The electrician installs the breaker, conductors and either the receptacle or the hardwired connection, then mounts the charger on the wall or pedestal using the template and hardware supplied.
- Set the current limit
If the charger has an adjustable current setting (DIP switches, a dial or the app), it must be set to match the circuit breaker as specified in the manual.
- Commission and test
Power up the unit, connect it to the network and app, and run a test charge. The inspector will usually check the installation before it is approved.
Network setup
Confirm a strong Wi-Fi signal (or run Ethernet, where supported) at the mounting location before installation — garages and outdoor walls are often weak spots. Register the charger in the manufacturer's app to enable scheduling, energy reports and firmware updates.
Using your EV charger
Starting and stopping a charge
- Park so the charge port is within reach of the cable without strain.
- Authorize the session if required — tap an RFID card, pay by credit card, or start it from the app.
- Insert the connector fully into the vehicle's port until it latches. The charger checks the connection and ground before it energizes the cable.
- Charging starts automatically unless the vehicle or charger has a schedule set. Check the vehicle display or charger indicator to confirm.
- To finish, end the session from the vehicle or app (or simply unlock the vehicle), press the connector release button, remove the connector and return it to its holster.
How long charging takes
| Energy added | Approximate range | Time at 9.6 kW |
|---|---|---|
| 20 kWh | about 60–80 miles | about 2 h 20 min |
| 40 kWh | about 120–160 miles | about 4 h 40 min |
| 60 kWh | about 180–240 miles | about 6 h 55 min |
Scheduling and smart charging
Use the app or the vehicle's own scheduler to charge during off-peak hours if your utility offers a time-of-use rate — set the schedule in one place only, because two competing schedules are a common reason a car does not charge.
Cable care during use
The 25 ft cable should hang or lie without kinks. Do not wrap it tightly around the unit, pull the vehicle forward while connected, or leave the connector lying in water or snow. In freezing weather, clear ice from the connector before inserting it.
Care and maintenance
| When | What to do |
|---|---|
| Every month | Inspect the cable and connector for cuts, crushing, bent pins or a damaged latch. Keep the connector and holster free of dirt, leaves and insects. |
| Every 3 months | Wipe the enclosure and cable with a damp cloth (power off for cleaning beyond a light wipe). Do not pressure-wash the unit or spray water into the connector. |
| Every 6 months | Check that the unit is still firmly mounted and that the cable strain relief at the enclosure is intact. |
| Every year | Have an electrician check the circuit connections and, for plug-in units, the receptacle for heat discoloration or looseness. |
| As released | Install firmware updates through the app or network platform; they can add features and fix charging or connectivity faults. |
| Every month (public sites) | Clean the display and card-reader faces and confirm payment and authorization work. |
Troubleshooting
Most charging problems come from schedules, connector latching or the vehicle's own settings. Work through these checks before calling for service.
| Problem | Possible cause | What to try |
|---|---|---|
| Vehicle will not start charging | Connector not fully latched; a charging schedule is set in the car or app; vehicle already at its charge limit. | Reinsert the connector until it clicks; check both the vehicle and charger schedules; confirm the vehicle's charge-limit setting. |
| Charger has no power or lights | Breaker tripped or switched off; GFCI tripped (plug-in units). | Check and reset the breaker or GFCI once. If it trips again, stop and call an electrician. |
| Charging is slower than expected | Vehicle onboard charger limit; current limit set below 40 A; cold or nearly full battery. | Check the vehicle's maximum AC charging rate; confirm the installer's current setting; charging naturally slows as the battery approaches full. |
| Charging stops partway through | Ground-fault or over-temperature protection activated; utility or app schedule ended the session. | Note any fault light pattern and look it up in the manual's fault table; check the session history in the app. |
| Ground-fault or fault indicator lit | Moisture in the connector; damaged cable; vehicle-side fault; wiring issue. | Dry the connector, try again, and test with another vehicle if possible. Repeated faults need an electrician or the manufacturer. |
| Connector will not release | Vehicle has locked the connector. | Unlock the vehicle or end the session from the vehicle; most EVs have a manual release described in the owner's manual. |
| Charger shows offline in the app | Weak Wi-Fi or cellular signal; changed router password; network outage. | Move the router or add an access point; re-run network setup; the charger normally still charges locally while offline. |
| Error code displayed | Brand-specific diagnostic code. | Error codes are not standardized; consult the code table in your manufacturer's manual or app before calling support. |
Energy use and running costs
ENERGY STAR certification for chargers focuses on the power the equipment itself consumes. With no vehicle connected, the Wolfbox E40 draws 3.7 W. Even if it sat in that mode around the clock, that would add up to about 32 kWh a year — roughly $5.51 per year at $0.17 per kWh. With a vehicle connected but not charging (idle mode) it draws 8.52 W.
While charging at full current, the charger's own losses were measured at about 10.6 W — roughly 0.11% of its 9.6 kW output — so nearly all the electricity reaches the vehicle.
The vehicle's consumption is far larger than the charger's. As an illustration, an EV driven 12,000 miles a year at about 3.5 miles per kWh needs roughly 3,771 kWh from the outlet including typical charging losses, or about $641 a year at $0.17/kWh. Charging on an off-peak time-of-use rate can reduce that substantially.
Frequently asked questions
How fast does the Wolfbox E40 charge?
It delivers up to 40 A, or 9.6 kW, which adds roughly 29–38 miles of range per hour if your vehicle can accept that rate.
What size breaker does the Wolfbox E40 need?
To run at its full 40 A output, it needs a dedicated circuit rated at least 50 A, because NEC rules treat EV charging as a continuous load sized at 125%. Have a licensed electrician confirm sizing and panel capacity.
Can the Wolfbox E40 plug into a NEMA 14-50 outlet?
A 40 A charger can run on a 50 A circuit, but only if your version is supplied with the matching plug — many units come in hardwired and plug-in versions. Check the model's configuration and use a GFCI-protected receptacle where code requires.
Does the Wolfbox E40 have Wi-Fi or app control?
Yes. It is network capable via Wi-Fi/Ethernet.
How long is the cable on the Wolfbox E40?
The output cable is 25 ft long. Plan the mounting location so it reaches the charge port without stretching.
How much power does the Wolfbox E40 use when not charging?
It draws 3.7 W with no vehicle connected, which costs about $5.51 a year even if it stays in standby continuously.
Sources and disclaimer
Specifications on this page come from the ENERGY STAR certified ev chargers dataset published by the U.S. Environmental Protection Agency (record certified April 18, 2024), retrieved October 7, 2026.
The setup, operating, maintenance and troubleshooting guidance is written by ManualHarbor's editors for this specific product type and configuration. It is an independent guide — not a reproduction of the manufacturer's manual — and ManualHarbor is not affiliated with Wolfbox. Always follow the safety instructions, installation requirements and warranty terms supplied with your unit, and contact Wolfbox or an authorized service provider for warranty repairs and replacement parts.
Running-cost figures use assumed U.S. average utility prices and are estimates for comparison only. See our editorial methodology for details.
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