As electric vehicles (EVs) become increasingly popular, choosing the right home charging solution is essential for convenience and efficiency. One of the key decisions EV owners face is selecting between a 32 Amp and a 40 Amp Level 2 charger. Both options provide faster charging than standard household outlets, but they differ in power output, installation requirements, and suitability for different driving needs.
The term "amp" (short for ampere) refers to the unit of electrical current—the rate at which electrons flow through a conductor. A 32 Amp EV charger delivers a lower constant current than a 40 Amp charger, meaning it charges at a slower rate. However, the right choice depends on factors such as your vehicle’s battery size, daily driving habits, and home electrical capacity.
This guide explores the differences between these two chargers, helping you determine which one best fits your needs.
A 32 Amp EV charger is a Level 2 charging station, typically supplying around 7.7 kilowatts (kW) of power when connected to a 240-volt circuit (common in residential installations).
Key Features:
Home-Friendly Installation: Most homes can support a 32 Amp charger without requiring major electrical upgrades.
Overnight Charging: Ideal for EV owners with average daily commutes (30-50 miles), as it can fully recharge most EVs in 8-12 hours.
Compatibility: Works with most modern EVs, including models from Tesla (with an adapter), Chevrolet, Nissan, and Ford.
Cost-Effective: Generally cheaper to install than higher-amperage chargers, as it uses a 40 Amp circuit (with a 20% safety buffer).
Pros:
Cost-Effective: Generally less expensive in terms of both equipment and installation compared to higher-amperage chargers.
Sufficient for Many Users: Meets the daily charging needs of average commuters, especially those with vehicles that have moderate battery capacities.
Cons:
Slower for Larger Batteries: May result in longer charging times for EVs with larger battery capacities or for users who require multiple charging sessions throughout the day.
Best For:
Drivers who charge overnight and don’t need ultra-fast charging.
Homes with standard electrical panels that can’t support higher loads.
EV owners with smaller or medium-sized batteries (e.g., Nissan Leaf, Chevy Bolt).
A 40 Amp EV charger is also a Level 2 charger but delivers more power—approximately 9.6 kW on a 240-volt circuit. This makes it significantly faster than a 32 Amp charger, reducing charging times by about 20-25%.
Key Features:
Faster Charging: Can add 25-35 miles of range per hour, compared to 18-25 miles with a 32 Amp charger.
Higher Electrical Demand: Requires a 50 Amp circuit (with a safety buffer) and may need a professional electrician to ensure compatibility.
Better for Large Batteries: More suitable for EVs with long-range batteries (e.g., Tesla Model S, Ford F-150 Lightning, Rivian R1T).
Flexibility: Useful for drivers with unpredictable schedules or those who need quick top-ups.
Pros:
Faster Charging: Ideal for EV owners with larger battery capacities or those who need quicker turnaround times between trips.
Future-Proofing: Better accommodates newer EV models with higher onboard charging capacities, making it a more future-ready investment.
Cons:
Higher Costs: Both the charger unit and installation may be more expensive, particularly if significant electrical upgrades are required.
Electrical System Limitations: Not all residential electrical systems can support a 50-amp circuit without modifications.
Best For:
EV owners with long commutes or high daily mileage.
Drivers who want faster charging and don’t want to wait overnight.
Homes with upgraded electrical systems that can handle a 50 Amp circuit.
32 Amp Charger: ~7.7 kW → Adds 18-25 miles per hour.
40 Amp Charger: ~9.6 kW → Adds 25-35 miles per hour.
Example: A Tesla Model 3 with a 60 kWh battery would take:
~8 hours to charge from 20% to 80% on a 32 Amp charger.
~6 hours on a 40 Amp charger.
32 Amp Charger: Needs a 40 Amp circuit breaker (NEMA 14-50 or 6-50 outlet). Most homes can support this without upgrades.
40 Amp Charger: Requires a 50 Amp circuit, which may need a panel upgrade if your home’s electrical system is older.
Cost Consideration:
A 32 Amp charger installation typically costs
500−1,200, depending on wiring distance.
A 40 Amp charger may cost
800−1,500+ if electrical upgrades are needed.
Both chargers consume similar total energy over time—just at different speeds.
Peak vs. Off-Peak Charging: A 40 Amp charger draws more power at once, which could slightly increase costs if used during peak hours. However, charging at night (off-peak) minimizes this difference.
Most EVs can accept up to 48 Amps (11.5 kW), so both 32A and 40A chargers will work.
If you plan to upgrade to a longer-range EV, a 40 Amp charger may be more future-proof.
Both chargers can be installed outdoors if they are weatherproof (NEMA 4-rated). Look for:
Durable enclosures (rust-resistant, UV-protected).
Safety certifications (UL, Energy Star).
Proper grounding to meet local electrical codes.
Pick a 32 Amp EV Charger If:
You have a smaller or mid-size EV (e.g., Nissan Leaf, Chevy Bolt).
Your home’s electrical panel can’t support a 50 Amp circuit without costly upgrades.
Pick a 40 Amp EV Charger If:
You drive long distances daily and need faster charging.
You own a long-range EV (e.g., Tesla Model Y, Ford Mustang Mach-E).
Your electrical panel can handle a 50 Amp circuit (or you’re willing to upgrade).
While a 40-amp charger draws more power and charges faster, the overall energy consumption for a full charge remains similar between the two chargers. However, charging at higher amperage during peak electricity rate periods could result in higher costs. To optimize expenses, consider scheduling charging sessions during off-peak hours, regardless of the charger's amperage.
The choice between a 32 Amp and 40 Amp EV charger ultimately depends on your driving habits, vehicle battery size, and home electrical capacity.
For most homeowners, a 32 Amp charger is sufficient, offering a balance between cost and performance.
For high-mileage drivers or those with large-battery EVs, a 40 Amp charger provides faster charging and better long-term flexibility.
Before purchasing, consult an electrician to assess your home’s wiring and ensure a safe, code-compliant installation.
Q: Can I plug a 32 Amp charger into a 50 Amp outlet?
A: Yes, but the charger will only draw up to its maximum (32A). You’ll need a NEMA 14-50 or 6-50 plug adapter.
Q: Does a 40 Amp charger shorten battery life?
A: No—EV batteries are designed to handle Level 2 charging. Fast charging (DC) is more impactful than AC charging.
Q: Can I upgrade from a 32A to a 40A charger later?
A: Yes, but you may need to upgrade wiring and circuit breakers, which can be costly.
By understanding these differences, you can make an informed decision and enjoy seamless EV charging at home!
