How to Choose an EV Charger: A Decision Guide

Most charger buying advice is a features comparison, which is the wrong shape for this decision. Charger selection is a sequence of constraints: each question you answer eliminates products, and answering them out of order is how people end up with a charger their house cannot feed or a cable that will not reach.

Six questions. In this order. By the end you will have a shortlist of two.

1. What circuit can your panel actually support?

Ask this before you look at a single product. It is the constraint that eliminates the most options and the one people leave until last.

Get a load calculation from a licensed electrician. It assesses your service capacity against your existing loads and tells you the largest dedicated circuit available. That single number determines your amperage:

• 60A circuit available→ you can run a 48A charger.
• 50A circuit available→ 40A charger. This is the common case.
• 40A circuit→ 32A charger.
• 30A circuit→ 24A charger. Still roughly 200 miles overnight.
• Panel is full → read our load management guide before accepting a service upgrade. There are cheaper answers.

The 80% figure is the continuous-load rule: a load running three hours or more may draw no more than 80% of its circuit rating, and EV charging is the textbook case. Our amps and circuits guide covers it fully.

While the electrician is there, ask what it would cost at each amperage and at a mounting point nearer the panel. The answers frequently change the whole plan — see our installation cost guide.

2. How much range do you actually need overnight?

The answer to question one is a ceiling. This question tells you whether you need to reach it.

Take your typical daily mileage. Then, roughly, for a typical EV:

• Level 1 (120V):~4–5 miles/hour → ~50 miles overnight
• 24A:~18 miles/hour → ~200 miles overnight
• 40A:~30 miles/hour → ~350 miles overnight
• 48A:~38 miles/hour → ~450 miles overnight

The average American drives around 37 miles a day. Read that against the list and the conclusion is awkward for anyone selling amperage: Level 1 covers the average driver and 40A covers essentially everyone. The extra amps buy hours you were asleep for.

The genuine cases for more: a very large battery regularly recovered from low, a short charging window, two EVs on one charger, or serious cold weather. Otherwise, our 40A roundup is where most people should be shopping, and if the answer to this question is small, Level 1 may genuinely be enough.

One more limit to check here: your car’s onboard charger. Many EVs cap AC charging at 32A or 48A. If yours caps at 32A, a 48A wall charger delivers 32A and the extra capability is inert.

3. Plug-in or hardwired?

Largely settled by question one — anything above 40A must be hardwired — but if you are at 40A you have a real choice, and it matters more than the amperage difference.

Plug-in(NEMA 14-50): the charger unplugs when you move, a failed unit is a five-minute swap rather than a service call, and you can mount and connect it yourself once the electrician has fitted the receptacle. The catch is that the receptacle becomes a component that can fail — and cheap ones genuinely do, so insist on an industrial-grade one.

Hardwired: removes the receptacle as a failure point, required above 40A, and permanently attached to the house. Entirely an electrician’s job to fit or replace.

Plug-in wins for most people, and decisively for renters — see our renter guide. The full trade-off is in plug-in vs hardwired.

4. J1772 or NACS?

Your car has one of two AC connectors, and so does every charger.

J1772 is what every non-Tesla EV in North America has used for over a decade. NACSis Tesla’s plug, now standardized, and increasingly fitted to new vehicles from other brands too. Our connectors guide explains the whole picture.

The strategic answer is more interesting than the obvious one. A J1772 charger plus a $40 adapter costs about the same as a native NACS charger and charges everything— your Tesla today, a visitor’s Ioniq tomorrow, whatever you buy in 2031. A native NACS charger is tidier for a Tesla-only household and needs its own adapter for anything else.

So: Tesla-only and staying that way→ native NACS is neater, and our Tesla charger roundup covers those. Any chance of a mixed fleet → J1772 plus the adapter, which is the more flexible purchase and the one we would default to.

5. How long a cable?

The most under-rated specification in the category, and the source of the most common regret. People optimize amperage — a few miles per hour they will never notice — and then discover the cable does not reach.

Walk the actual pathbefore buying: from the mounting point, down the wall, across the floor, around the car to the charge port, plus slack so the cable is not under tension. Add a couple of feet. Then compare to the charger’s published length.

Two things follow. First, buy 25 ft over 16 ft if the price difference is small; it is almost always worth it. Second — and this is the cost insight — a long cable lets you mount the charger near the panel and reach the car, rather than running expensive conduit to a charger near the car. That is frequently the single largest saving in the whole installation.

If the cable genuinely will not reach, the fix is a properly rated J1772 extension— never a household extension cord, which under a 40A continuous load is a real fire risk.

6. Do you need it to be smart?

Last, because it should be. Three features justify the price; everything else is a dashboard you will stop opening.

• Off-peak scheduling— genuinely saves money if your utility has time-of-use rates. But check your car first; most modern EVs schedule from their own screen for free, and then a charger app is a duplicate.
• Load management— the one thing your car cannot do. If your panel is tight, this can avoid a service upgrade, which makes it the most valuable feature on this list by a wide margin.
• Access control— matters if the charger is somewhere others can reach it. Irrelevant in a locked garage.

If none apply, a simple charger is not a downgrade — it is one fewer radio, firmware image and cloud account that can fail. Our smart charger roundup covers what is worth paying for, and our budget roundup covers the honest floor.

The one thing that is not negotiable

Whatever you conclude on the six questions above, buy nothing that will not name its certification body in plain text. UL or ETL, from a named laboratory. Not “certified”, not a logo you cannot identify, not silence.

This is a device that draws its full rated current continuously for eight to twelve hours, unattended, usually in an attached garage, for a decade. Very few household products work that hard. The EPA’s ENERGY STAR program publishes a searchable list of certified EV chargers and checking a model against it takes under a minute. Do it. It is the cheapest insurance in the entire purchase, and it is the one specification where price is never a reason.