Two Teslas can plug in at the same Supercharger site and get very different charging speeds, even with similar batteries and similar states of charge. Part of the reason is which stall each car happens to use, not just which site it’s at.
The biggest factor is which hardware generation is bolted to the ground at that stall.
V3 versus V4, in plain terms
“V3” and “V4” refer to the power cabinet that feeds a row of stalls, not the stall itself. Tesla’s V3 cabinet, which the company built for about seven years before retiring it, tops out at 250 kW per car and was designed around the 400-volt electrical systems used in the Model S, 3, X, and Y. Tesla’s newer V4 cabinet raises the ceiling to up to 500 kW and supports a much wider 400-to-1,000-volt range, which is what lets Cybertruck’s 800-volt battery pack charge meaningfully faster there than it can on V3. A single V4 cabinet also feeds up to eight stalls, twice what a V3 cabinet handles, according to reporting on the V3-to-V4 transition. For most Model S, 3, X, and Y drivers, though, a V4 stall currently still delivers around the same 250 kW peak they’d get on V3 — the 500 kW ceiling is mainly for Cybertruck and future 800-volt vehicles for now.
So the generation printed on the cabinet sets a hard ceiling on your charging speed before your neighbor ever factors in.
Why the stall next to you can matter
At many older Supercharger sites, stalls are wired in pairs that share one power cabinet — think of stalls labeled 3A and 3B. If you’re alone at 3A, you can pull the cabinet’s full output. If someone pulls into 3B while you’re charging, the cabinet splits its power between you, and your charging speed can drop to roughly half what you were getting, especially early in the session when charging rates are highest. This paired setup is a feature of Tesla’s older 150 kW and slower Superchargers. On V3 and V4 hardware, each stall gets its own dedicated power electronics, so a neighbor plugging in next to you doesn’t cut your rate.
Picking a faster stall
A few things help when speed matters:
- Check the hardware first. If a site mixes older and newer cabinets, or if your route options include both an older V2-era station and a nearby V3/V4 one, the newer cabinet is the safer bet for a full-speed charge.
- At older, paired stations, don’t sit next to an active charger. If stall 3A already has a car plugged in and charging, skip 3B and take an unpaired or fully empty pair instead, per the same CleanTechnica breakdown of Supercharger pairing.
- Use the live occupancy view before you commit. Tesla’s in-car navigation and app have shown real-time stall-by-stall status since Tesla first rolled it out in 2017, and as of December 2025 Tesla was piloting a 3D site map at select stations that shows each stall as available, occupied, or down before you pull in.
None of this changes what your car’s battery and battery percentage can accept — that’s a separate ceiling of its own. But the stall you plug into sets a hard limit on top of it, and that limit can vary from one charger to the next at the very same site.
Photo by Giant Asparagus.