No. Your electricity price is set per kilowatt-hour by your utility plan, and it is the same whether that energy flows through a small charger or a large one. A bigger charger changes how fast the energy arrives, and it can slightly change how much total energy a session uses — but it does not change the price of each unit, and it cannot push more power into a car than the car can accept.
Key Takeaways
- Electricity is priced per kWh; charger size changes speed, not the unit price.
- The car’s onboard charger caps the rate, so unused capacity costs nothing to run.
- Faster charging trims session losses slightly; the big saving is finishing inside an off-peak window.
- An adjustable-current charger lets you match speed to your circuit and your tariff.
Your Rate Does Not Care About Charger Size
Think of the charger as a wider or narrower pipe, and the meter as counting volume. Widening the pipe does not change the price per litre. The same applies at home: 40 kWh delivered to your battery costs the same at 16 A as at 48 A, before losses.
The table adds 40 kWh to a battery at 240 V, assuming about 10% charging losses (so about 44.4 kWh comes from the wall) and the EIA average residential price of 18.31 cents per kWh. Only the time changes.
| Charger setting | Power at 240 V | Time to add 40 kWh | Energy cost from the wall |
|---|---|---|---|
| 16 A | about 3.8 kW | about 10.5 hours | about $8.15 |
| 32 A | about 7.7 kW | about 5.2 hours | about $8.15 |
| 40 A | 9.6 kW | about 4.2 hours | about $8.15 |
| 48 A | about 11.5 kW | about 3.5 hours | about $8.15 |
There is also a ceiling set by the car. A charger rated above your car’s onboard charger limit simply runs below its rating; the surplus capacity costs nothing extra to operate. This is worth understanding before paying for capacity a car cannot use, as Is a Level 2 Charger Worth It? discusses.
Where Size Does Change the Bill Slightly
The one real difference is losses over time. While a session runs, the car’s computers, pumps and battery heating draw a roughly steady amount of power that never reaches the battery as range. A shorter session spends fewer hours on that overhead. This time effect is the main reason Level 2 works out about 10% more efficient than Level 1 on average, as ENERGY STAR reports and as the Level 1 versus Level 2 electricity comparison explains.
Between two Level 2 sizes, the effect is much smaller — an hour or two of overhead, not the overnight-long sessions of Level 1. In cold weather, a faster charger also spends a smaller share of the session warming the battery. Treat both effects as a few percent at most, not a reason to buy the largest charger available.
The Case Where Speed Really Saves Money: Your Rate Window
On a time-of-use plan, when the energy arrives matters more than how fast. A bigger charger can finish the whole session inside a short off-peak window, while a smaller one may still be running when peak prices return. Finishing inside the cheap window is a genuine saving; the charger size is just the tool that makes it possible. The mechanics are covered in Smart Charging and Time-of-Use Tariffs.
An adjustable charger gives you both options in one unit. The EVDANCE EV-ACS4005T 40A NACS portable charger (9.6 kW, NEMA 14-50P, IP66) can be set to 16, 24, 32 or 40 A, so you can run it gently on a limited circuit or at full speed to beat a tariff deadline.
Frequently Asked Questions
Will a 48 A charger raise my electric bill?
Only if you drive more. It adds the same energy in less time; the bill follows total kilowatt-hours, not charging speed.
Does charging faster use more electricity overall?
Slightly less, if anything. Shorter sessions mean fewer hours of the car’s systems running during charging, which trims losses a little.
Is a smaller charger cheaper to run?
Not per kWh. A smaller charger may be cheaper to buy and install, but running cost per unit of energy is set by your electricity plan.
Related Reading
- Does Level 1 Charging Use More Electricity Than Level 2?
- How Much Does It Cost to Charge an Electric Car at Home?
- Is a Level 2 Charger Worth It?
- Smart Charging and Time-of-Use Tariffs: How Scheduling Cuts EV Charging Costs
