Why 40 amps is the number most homes should buy
The appeal of a 40-amp charger isn’t the charger — it’s the circuit behind it. EV charging is a continuous load, so the National Electrical Code sizes the branch circuit to 125% of the charger’s draw(the “80% rule”). Run that math backwards and a 40-amp charger needs a 50-amp circuit, while a 48-amp charger needs a 60-amp one. A 50-amp circuit is common, it’s exactly what a NEMA 14-50 outletis wired for, and it’s far more likely to fit in an existing panel without an upgrade. That is the whole reason 40 amps and plug-in installs travel together: pick 40 amps and you can usually skip both a panel upgrade and a hardwired job.
And you give up very little speed for that. At 40 amps a charger delivers 9.6 kW, which on a reference 3.5 miles per kWh EV works out to roughly 34 miles of range per hour. A 48-amp charger makes about 40. Over a normal overnight charging window — you’re asleep for eight hours, the car needs to replace maybe 30 to 50 miles — that six-mile-per-hour gap is invisible. We work the whole comparison through in 40 amps vs 48 amps; the short version is that 48 amps earns its extra circuit only for very high-mileage drivers on a tight refill schedule.
Before you shop, confirm what your panel can actually spare with our panel-capacity guide. If a 50-amp circuit fits, a 40-amp charger is very likely the right call; if even that is a stretch, some of these units dial down further still.
Native 40-amp vs a bigger charger set to 40
There are two honest ways to get a full 40 amps, and the table below sorts our picks into both. A native 40-amp charger — the Grizzl-E Classic and the Lectron 40A— is built for exactly this circuit and priced accordingly; there’s no headroom to pay for and none to unlock. A higher-rated unit — the ChargePoint Home Flex (adjustable 16–50A), the Emporia (48A hardwired, 40A on a plug) and the Autel MaxiCharger(50A) — is set to 40 amps to run cleanly on a 50-amp circuit today, and can be turned up later if you ever move it to a bigger circuit. You pay a little more now for that option.
Every unit here delivers a full 40 amps — 9.6 kW, about 34 miles of range per hour at ~3.5 mi/kWh. Two are native 40-amp chargers; three are higher-rated units you set to 40A to run on a standard 50-amp circuit. Specs are read from each maker’s own spec sheet.| Charger | Rated max | How it makes 40A | Install | Cable | App |
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| ChargePoint Home Flex | 50 A | Set to 40A in the app (adjustable 16-50A) | Hardwired (plug-in NEMA 14-50 SKU also sold) | 23 ft | Yes |
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| Emporia Level 2 EV Charger | 48 A | 40A on a NEMA 14-50 plug (48A hardwired) | Hardwired or NEMA 14-50 plug | 25 ft | Yes |
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| Grizzl-E Classic | 40 A | Native 40A | NEMA 14-50 plug | 24 ft | No |
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| Lectron 40A Portable Level 2 Charger | 40 A | Native 40A | NEMA 14-50 plug | 16 ft | No |
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| Autel MaxiCharger Home | 50 A | Set to 40A on a 50A circuit (50A max) | Hardwired | 25 ft | Yes |
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Neither approach is “better” in the abstract — it depends on how settled your plans are. If you know 40 amps is your ceiling (renting, a modest panel, no interest in a future rewire), a native unit is the cleaner buy. If you might upgrade the panel someday, or you want the most capable app, an adjustable charger is a reasonable hedge. What you should notdo is overbuy amps you can’t reach: a 48-amp charger on a 50-amp circuit just runs at 40, so you’d be paying for a number you can’t use.
The picks, in plain terms
The ChargePoint Home Flexis our overall pick because it fits the most homes with the fewest regrets: adjustable amperage means one charger works on a 50-amp circuit now and a bigger one later, the app is the most mature here, and the warranty is long. It’s a premium price for that flexibility — if you want the same idea for less, read our full Home Flex review and then weigh the value picks below.
The Emporia Level 2is the value-smart choice: a genuine app with real energy monitoring, an ENERGY STAR listing, and a long 25-foot cable for well under the big-name price. On a NEMA 14-50 plug it runs at 40 amps, and it can be hardwired to 48 later — a tidy way to buy 40 amps now with room to grow. Our Emporia review has the detail. The Grizzl-E Classic goes the opposite direction on purpose: a native 40-amp, die-cast aluminum box with noapp, no account and no firmware to fail — you schedule charging in the car instead. If “set it and forget it” is the goal, its simplicity is the feature, as we explain in the Grizzl-E review.
The Lectron 40Ais the cheapest honest way into real Level 2 charging: a native 40 amps, ETL-listed to the UL 2594/2231 safety standards, and portable, so you can unplug it and take it along. The trade-offs are a shorter 16-foot cable, a two-year warranty, no app on the base model, and no published outdoor rating — fine for a garage, not for an exposed wall. When price is the whole story, it’s also on our budget charger list. Finally, the Autel MaxiChargeris here for one specific buyer: someone who wants a 40-amp install but whose charger has to live fully outdoors. Its NEMA 4X enclosure is rated for corrosion, cold and heat; set it to 40 amps on a 50-amp circuit now, and it has room to 50 amps if you upgrade. The catch is that its full output is a hardwired, 60-amp-circuit job — at 40 amps you’re buying the weatherproofing, not the speed.
Plug in, or hardwire?
Forty amps is where the plug-in route makes the most sense, and it’s worth being deliberate about it. A plug-incharger drops onto a NEMA 14-50 outlet, stays removable if you move, and skips the electrician’s hardwiring labor — but the receptacle itself needs a proper 50-amp install, and under current code that circuit generally needs GFCI protection, usually a GFCI breaker. A hardwiredcharger has no plug to weatherproof and can, on some units, run at higher amperage — but it’s a permanent install and removes the renter-friendly flexibility that makes 40 amps attractive in the first place. Our hardwired vs plug-in comparison weighs the whole trade, and the NEMA 14-50 guide covers the outlet and its code requirements.
Whichever way you connect it, budget the job before you buy the box. Hardware is only part of the bill — the circuit run, the outlet or hardwiring labor, the permit and any panel work all move the total, and we break every line down in the installation cost guide.
How to choose between these five
Start with how permanent your setup is. If you rent, or you just want the lowest price for real 240V charging in a garage, the Lectron 40Ais the budget answer. If you want a charger you never have to think about — no app, nothing to update — and don’t mind scheduling in the car, the Grizzl-E Classic is the rugged, native-40A workhorse. If you do want scheduling and energy data without the big-name markup, the Emporiais the value-smart pick with the longest reach. If you want the most flexible, most future-proof charger and the best app — and you’ll pay for it — the ChargePoint Home Flex is the safe default. And if your charger has to survive a fully exposed outdoor spot, step up to the Autel MaxiCharger for its weather-rated enclosure.
Every one of these delivers the same core thing: a full 40 amps, 9.6 kW, about 34 miles of range an hour, on a circuit most homes can carry. The differences are the app, the build and the cable — convenience and durability, which are real but optional. Once you’ve chosen, it’s worth a minute with our cost-to-charge calculatorto see what those overnight kilowatt-hours actually cost on your electric rate — the part no charger brand puts on the box.
