Two houses on the same street can get quotes for the same charger that differ by a factor of four. Nothing dishonest is happening: one of them has a service with room to spare and a panel on the garage wall, and the other needs a service upgrade and a forty-foot cable run. This is what sits behind that gap.
What you are actually paying for
A Level 2 charger installation is four things, and only one of them is the charger:
- The unit itself, which you may already have bought, and which many installers are happy for you to supply.
- A dedicated 240V circuit — breaker, cable, and the run from the panel to wherever the car parks.
- The load calculation and any service work it triggers. This is the part that varies most, and the part nobody can quote from a photograph.
- Permit, inspection and commissioning. Fixed-ish, set locally, and small relative to the rest.
The middle two are where the money is. Everything below is about them.
The load calculation decides most of it
A charger is a continuous load, which means it is calculated at its full rating rather than at an average. That matters: a charger drawing 48 amps is treated as drawing 48 amps for hours, not as an appliance that cycles.
The calculation totals what the house already demands — general lighting and receptacles, fixed appliances, heating and cooling, anything on a dedicated circuit — applies the standard demand factors that account for not everything running at once, and compares the result against your service rating. There is either room for the charger or there is not.
This is arithmetic, not opinion, and it is the fork in the road. Room in the service means a straightforward single-visit job. No room means a second, larger piece of work, and the quotes diverge from there. What a panel upgrade costs, if it comes to that
Houses in the Lawton area with gas heating and gas water heating often have more headroom than their owners expect. Houses that have added central air, an electric range or a hot tub since the service was installed often have less.
Circuit size, and why 48 amps needs a 60-amp circuit
Because a charger is a continuous load, its circuit is sized above its draw rather than to it. A 48-amp charger goes on a 60-amp circuit; a 40-amp charger goes on a 50. That affects the breaker and, more importantly, the cable gauge — and heavier cable over a long run is a real line item.
Worth knowing before you buy: most chargers can be configured to draw less than their maximum. Dialling a 48-amp unit down to 40 or 32 often costs nothing you would notice overnight, and it can be the difference between fitting inside your existing service and not. If a quote assumes maximum output without asking how you actually drive, that is a fair question to raise.
Distance from the panel
After the load calculation, this is the biggest variable, and it is pure geometry. A charger on the other side of the wall from the panel is a short run through one penetration. A charger at the far end of a detached garage is a long run of heavy cable, possibly a trench, possibly a subpanel out there instead.
What tends to move it:
- Whether the route is open — an unfinished garage or basement is much cheaper than a finished wall.
- Whether it goes outside, and therefore needs conduit and weather-rated fittings.
- Whether it crosses to a detached structure, which is a different job again.
- Which side the car’s charge port is on. Worth deciding before anyone quotes.
This is the part you can influence for free. Choosing a spot ten feet closer to the panel, or accepting a slightly less convenient wall, can move the number more than choosing a different charger will.
Hardwired or plug-in
A hardwired charger is connected directly and is the more robust arrangement, especially outdoors. A plug-in unit sits on a 240V receptacle and can be unplugged and taken with you, which suits a rental or someone who expects to change units.
The cost difference is usually small — a receptacle instead of a whip. Two things are not about money: some higher-current chargers must be hardwired, and a receptacle used daily for a high continuous load wears in a way a fixed connection does not. Both are proper installations; the choice is about permanence rather than price.
If the panel is full or the service is short
This is the scenario that doubles a quote, and there are three legitimate answers rather than one:
- A service upgrade. The complete answer, and the right one if you also want a generator, a heat pump or a workshop later. It brings in permits and the utility.
- Configure the charger lower. Free, and often enough when the shortfall is small.
- A load management device. Prevents the charger and another large load drawing at full rate simultaneously, so the service is never over-committed. Cheaper than an upgrade, and genuinely the right answer for some houses.
A quote that jumps straight to a service upgrade without mentioning the other two is worth questioning. So is one that ignores a genuine capacity problem to look cheaper. How panel and service work is scoped
Permits and inspection
A new dedicated circuit normally requires a permit and an inspection, pulled by the licensed contractor rather than by you. The fee is set locally and is a small share of the total — but a quote that omits it is not cheaper, it is incomplete. How permits work in Lawton
The cheaper options, and what they cost you
A 240V receptacle instead of a wall charger. You use the portable cable that came with the car. Less up front. You give up charging speed, scheduling and monitoring, and the circuit behind it — the expensive part — is identical either way.
Sticking with Level 1. The cable in the boot, plugged into an ordinary outlet. No installation cost at all. It adds a few miles of range per hour, which suits a plug-in hybrid or a short commute and frustrates everyone else. If you go this route, a dedicated circuit is still worth having: a charger sharing a circuit with other loads is a common cause of nuisance tripping.
What is not an option: DC fast charging at home. It needs a three-phase supply and equipment at a scale residential service does not provide. Anyone offering it for a house is not worth continuing the conversation with.
Reading two quotes properly
Before comparing the numbers, check both include the same work:
- Has a load calculation actually been done, or assumed?
- What charger current is each quote sized for? A 32-amp install is not a 48-amp install.
- Is the permit and inspection included?
- Is the cable run the same route, and does either involve a trench or a detached structure?
- Does either include service or panel work, and is the other quietly assuming it is not needed?
- Is the charger supplied, or are you buying it?
The most useful single question, as with any electrical quote: what is not in this price?
EV charger installation — what the work involves · How electrical pricing is structured