You bought the car. The charger is sitting in the garage in its box. And somewhere between the two is a question nobody at the dealership brought up: can the electrical panel on the side of your house actually handle it?
Usually, yes. But “usually” is doing some work in that sentence, and in Central Texas in late August it is doing more work than it would in November.
The charger isn’t the hard part. The panel is.
A Level 2 home charger runs on a 240-volt circuit, the same kind of supply your dryer or range uses. The difference is that it pulls that power for hours at a stretch. Electricians call that a continuous load, and it gets treated differently from something that cycles on and off. The circuit has to be sized above the charger’s rated draw rather than right at it, so a 40-amp charger does not go on a 40-amp breaker.
That part is straightforward. What is not straightforward is whether your panel has room for that circuit once everything already in the house is accounted for.
What we actually look at
1. The size of your electrical service
This is the number stamped on the main breaker at the top of the panel. Most Central Texas homes built in the last twenty-five years have a 200-amp service. Older houses, and there are plenty around here, may have 100 or 125 amps. Whatever that number is, it is the ceiling for everything in the house combined.
2. What is already drawing on it
A load calculation adds up the real demand of the house: air conditioning, water heater, range, dryer, pool pump, a shop out back, and any solar or battery equipment already tied in. Then it adds the charger. If the total stays under the service size, you are fine. If it does not, you still have options, and a service upgrade is only one of them.
3. Whether there is physical room for the breaker
Capacity and space are two different problems. A panel can have plenty of headroom on paper and no open slots left to land a two-pole breaker in. Sometimes there is a clean answer, like a subpanel or a rearrangement of what is already there. Sometimes there is not, and it is better to know that before the charger is out of the box.
4. The run from the panel to where you park
Distance matters, and so does what the wire has to pass through. A charger on the garage wall directly behind the panel is a different job from one on the far side of a detached garage. This is usually where two otherwise identical installations stop being identical. We walk it before we quote it, and we explain what we found. If you want to understand what moves the number on a panel job specifically, we wrote about what drives electrical panel upgrade cost.
If the numbers don’t work, an upgrade isn’t the only fix
This is the part homeowners are most often surprised by. Coming up short on a load calculation does not automatically mean a new service.
- Turn the charger down. Most Level 2 units let you set a maximum current during setup. A charger set lower still fills the battery overnight for typical daily driving. You are asleep either way.
- Load management. There are devices that watch the whole house’s draw and pause or throttle charging when demand spikes. That lets a charger coexist with a service that could not otherwise carry it.
- A dedicated subpanel, when breaker space rather than capacity is the constraint.
- A service upgrade, when the house was going to outgrow the panel anyway. If a battery, a heat pump, or a second EV is anywhere in your thinking, doing the work once makes more sense than doing it twice.
We will tell you which of those applies to your house. If the honest answer is that you do not need the upgrade, that is the answer you will get.
The late-summer wrinkle
Right now your panel is working as hard as it works all year. In August a Central Texas house runs its air conditioning through the afternoon and deep into the evening, and that is the load a new charger would be stacking on top of.
That is not a reason to wait. It is a reason to have the calculation done against real summer demand instead of a mild-weather guess, and a reason load management is worth a look if your service is already close to its limit. A charger that steps back for an hour on a 105-degree afternoon and catches up at two in the morning is not costing you anything you will notice.
What to have ready
Before we come out, it helps if you know:
- Which charger you bought, or are looking at, and its amperage
- Roughly where you want to park and plug in
- Whether you already have solar, a battery, or a generator
- Whether the panel has ever been upgraded
If you do not know any of that, that is fine. Most people do not. We will look.
Talk to a local electrician
Aether Energy is a licensed electrical contractor, TECL #35881, serving Austin, Kyle, Buda, San Marcos, New Braunfels and the surrounding Hill Country. We assess panel capacity, install the circuit, pull the permit, and hand the job over working. You can read more about our home EV charging work, or about EV charger installation in Austin specifically.
Book your assessment and we will tell you what your panel can take.
