Does the Ioniq 5's 800V system change anything about a home Level 2 setup, or is it purely a DC fast charging thing?
I test Level 2 chargers for a living — installs, apartment lots, multi-user parking, the whole range — and I still second-guessed myself buying a charger for my own driveway last month, which tells you something about how much marketing noise is out there around 800V.
I picked up a 2025 Ioniq 5 in July. Every spec sheet and every sales conversation leans hard on the 800V architecture like it's a headline feature for home charging too, not just the DC fast charging use case. Before I signed off on a home unit I wanted to actually check that assumption instead of defaulting to the highest-amperage option out of habit, which is what I'd tell a client to do in my job anyway.
From what I can tell, the 800V platform is entirely a DC fast charging thing — it's how the car bypasses the onboard charger at a DCFC station and pulls current more efficiently at the pack level. At home on 240V AC, none of that applies. Everything routes through the car's onboard charger the same way it would on any 400V EV, and that charger has its own ceiling regardless of what the wall unit can deliver.
Before I spend money on a higher-capacity unit than the car can actually use, can someone confirm the actual onboard charger ceiling on this model year, and whether there's any real home-charging benefit to 800V I'm missing? I have a detached garage, no existing circuit run yet, so I'm deciding the amperage before anything gets installed, not retrofitting.
Filed under: Home Charging & NEMA Outlets
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13 answers
13 ANSWERS
@orbit_snackSeptember 02, 2026
You're right, and here's precisely why. The 800V pack lets the car accept a much higher current at a DC fast charger without the resistive losses (and heat) a 400V pack would see at the same power level — that's the entire benefit, and it only exists because the charger outside the car is doing the DC conversion, not the car itself. On Level 2 AC, the car's onboard charger does that conversion, and Hyundai's onboard charger on 2024 and newer Ioniq 5s tops out at 10.9 kW, which works out to about 46A at 240V. Doesn't matter if the EVSE on the wall can push 48A or 80A, the car will never pull past that number. 800V or 400V, the OBC ceiling is what actually gates you at home.
@pixelmango19August 28, 2026
This is exactly the mismatch I see reviewers get wrong constantly, myself included early on. A 48A EVSE on this car wastes about 2A of headroom, which is functionally nothing, don't sweat that purchase. But a 19.2 kW / 80A-capable unit is a different story. That's pure overspec for this car specifically. You're paying for capability the Ioniq 5 physically cannot use on AC no matter what you plug it into, full stop. That spec is worth paying for on something like a Ford F-150 Lightning with the Charge Station Pro, where the vehicle can actually use 80A. Not here.
That confirms what I suspected — appreciate the F-150 comparison, that's a useful contrast case for explaining this to people who aren't going to read a spec sheet. Given I don't need to protect against some future higher-capacity car, since I'm buying for this Ioniq 5 specifically and would just install new if I ever changed vehicles, is there an actual sweet spot below 48A that makes sense, or is 48A basically the default answer once you're spending the money anyway?
@rustlanternAugust 29, 2026
There's a real sweet spot and it's not 48A. A 40A EVSE on a 50A circuit gives you 9.6 kW, which is about 88% of what the OBC can actually use. You're leaving a little charging speed on the table compared to a 46-48A setup, but the install cost difference is real — a 50A circuit is a meaningfully smaller wire gauge and often a smaller breaker footprint than sizing for the full 60A circuit a 48A EVSE wants once you add the code margin. For most home charging patterns, plugging in overnight, that 12% speed difference doesn't change anything about whether the car's full by morning. It only matters if you're doing same-day top-ups on a tight window.
Flagging the panel side of this before anyone commits to an amperage. A 40A EVSE circuit needs about 8 kW of continuous headroom on your panel's load calculation, and that's a real problem for a lot of houses still running 100A main panels, which is more common than people assume outside of new construction. You don't necessarily need a full panel upgrade to solve that. A load-management device — something like an Emporia energy monitor, or a Wallbox Pulsar Plus with its built-in energy meter, that dynamically pulls back the EVSE's draw when the rest of the house is under load — typically adds $150 to $300 to the install. A 200A panel upgrade to get the same headroom without load management usually runs $2,000 to $3,000. If your panel already has room this is moot, but pull your panel schedule and confirm rather than assuming you need the upgrade.
I've watched both sides of this call play out on jobs and I'll be honest, I lean away from load management for anyone who isn't tight on budget, even though the math favors it. It's one more device that can fail or get bypassed by a homeowner who doesn't understand why their charging slowed down on laundry day. My own install was the boring version — new 60A line, no load management, paid $1,500 total for the charger and the run. More expensive up front than the Emporia route would've been, but it's just a breaker and a wire, nothing to configure or troubleshoot later. Not saying Marcus is wrong, the cost math checks out, just a vote for the simpler failure mode if your panel can actually support it without an upgrade.
@duskravenAugust 27, 2026
My cousin outside Calgary has the same car and went through this exact decision this spring. His electrician quoted him $2,000 to $3,000 CAD, and most of that quote was panel-related work, not the charger or the circuit itself. Older house, so it tracks with what Marcus is describing about 100A panels being more common than people think. He ended up doing the panel work rather than a load-management box because he's planning to add a heat pump in a couple years anyway and wanted the headroom for that too, not just the car.
Relevant to me since I went through the outlet-type decision on my Ioniq 5 a couple months back, 6-50 instead of 14-50, panel had headroom so that part was easy. Actual EVSE purchase and circuit are still sitting undone though, turns out Level 1 has covered my daily driving fine so it hasn't been urgent. This thread is useful for when I do get around to it, sounds like 40A on the 50A circuit is what I'd land on once it stops being a hypothetical.
@silverpickleAugust 31, 2026
Since model year hasn't come up yet — if anyone here has a 2022 Ioniq 5 and is seeing charge rates noticeably below what they'd expect from the math in this thread, it's worth checking for a firmware update before assuming the EVSE or circuit is the problem. My sister's 2022 was charging slower than it should've been on a 40A circuit for about a year before a dealer update fixed it. Hyundai patched a charging-rate issue on that model year at some point. Wasn't the outlet, wasn't the breaker, was the car.
@picklewindowAugust 27, 2026
I got my Ioniq 5 in the window when Hyundai was running the free ChargePoint home charger promo, and between the free unit and an installer who already knew the promo paperwork, my total out of pocket was $600. That was an existing circuit with enough capacity already there, so none of the panel-upgrade cost people are describing above applied to me. Ask your dealer or installer whether that promo or something similar is still running before you price out a unit on your own.
@windowpane_rAugust 25, 2026
The 48A-is-pointless math checks out, but here's what it costs you later if you skip it. If you're already paying an electrician to be there and the difference between wiring for 40A and wiring for 48A is basically the outlet and a slightly bigger breaker, not a whole different circuit size, I'd just do 48A. Not because this Ioniq 5 needs it, it doesn't, but because whatever replaces it in 8-10 years almost certainly will, and ripping out a circuit to redo it later costs a lot more than the marginal cost would've been now. Different answer if you're on a 50A-max panel budget where every amp costs real money, I get that trade-off is different.
That's a fair trade-off and depends a lot on whether you'd actually reinstall versus move. One thing from the testing side though: I've seen more early connector and receptacle wear on units running consistently close to their max rated amperage than on units with headroom, hours matter less than how close to the ceiling the draw sits every single day. Doesn't change your resale logic, but it's part of why I lean toward sizing for the car in front of me rather than the hypothetical next one, if I'm the one plugging in nightly for the next several years.
@copperleaf_wAugust 25, 2026
For anyone reading this later and wondering if the 40A-on-a-50A-circuit setup is actually code compliant and not just a cost hack: it is. The code caps continuous load at 80% of the breaker rating, and 40A is exactly 80% of 50A, so that circuit is sized correctly at the boundary, not skirting it. A 48A EVSE needs a 60A breaker under the same rule, which is where the bigger wire and often the bigger panel footprint comes from. Nothing wrong with either choice, just wanted the code reasoning in here since half this thread is really a code-sizing question wearing an Ioniq 5 costume.
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