Finding hardware fast enough to stretch the new BMW iX3 is half the challenge, so Out of Spec Roaming took it to one of Europe's first 1,000 volt capable Tesla V4 Superchargers, in Norway, to run a full 10 to 80 percent analysis with battery temperature logging. The result is a clean one. The host reports the iX3 jumping straight to its advertised 400 kW peak, pulling over 500 amps, and completing 10 to 80 percent in 21 minutes, matching BMW's own claim. The car in the test carries a 113 kWh battery with 108.7 kWh usable, an NMC chemistry built on cylindrical 4695 cells, and a true 800 volt architecture, with pack voltage sitting around 765 to 800 volts near the top of the charge.
The interesting tension here is heat versus density. BMW clearly prioritized energy density in this pack, and the host frames that as a road trip advantage: enough range that you may skip a stop entirely. He puts the peak C rate at around 3.5, which he calls solidly mid pack rather than class leading. Worth adding for buyers weighing 400 volt against 800 volt cars: the higher voltage means less current for the same power, which usually means less heat, and it is also what lets the iX3 take full advantage of newer 1,000 volt capable chargers as Tesla and others roll them out across Europe. That charger rollout is the real story behind this test. A year ago there was almost nowhere to see 400 kW from a car like this. The takeaway is that a fast car is only as fast as the network underneath it, and that network is finally starting to catch up.
The host notes this battery likes to be preconditioned to around 30 to 35C before a fast charge, and that its NMC chemistry needs less winter warming than an LFP pack would, so he expects similar speeds in cold weather as long as drivers remember to precondition. Despite the 800 volt setup, he records the battery climbing to 59C during the session, which he calls hot, and he attributes a mid session taper to the pack protecting itself. He still rates the outcome highly, noting the car hit BMW's advertised time and that the temperature dropped back to around 30 to 35C quickly once driving resumed, which he reads as strong thermal management. He describes the 21 minute result as a chemistry limitation rather than a hardware one, slower than some Chinese competitors that manage 16 minutes or less, but paired with a very large usable battery and strong efficiency. He praises the car's information rich charging display, which shows amps and pack voltage, notes a lower 107 kW rate by 80 percent that he argues matters less given how much range sits at that point, and says a separate 15 minute road trip range test is still to come. Away from the charger, the host is plainly enthusiastic, calling it one of the best SUVs out there and saying it feels like a proper BMW to drive. He even frames the car's central trade off as a question for viewers: would you take this big, dense, efficient battery and skip charging stops on most trips, or pick a car that charges faster but needs to stop more often on a long haul?
Bottom line: The iX3 makes a specific bet: carry a big, dense, efficient battery, and win the road trip by needing fewer stops rather than by charging the fastest. On this evidence it delivers, hitting its numbers on hardware that can finally feed it. The 59C reading is the one thing to keep an eye on over a car's life, though the quick cooldown the host observed is reassuring. If your driving is long hauls with occasional charges, this approach suits you. If you live at the fast charger, a car built to charge in 16 minutes may fit better.
Commentary on a third-party video. Figures and claims are as presented in the source and have not been independently verified. Spotted an error? Tell us and we will correct it.