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.