UK update
500 kW Stalls, Modelled as Session Time
Sam Whitfield, UK EV writer & Tesla owner · filed
Peak rate is a cabinet specification. What matters to a reward holder is how many stops it takes to spend 650 miles, and how long each one blocks out.
Tesla's V4 cabinets are quoted at up to 500 kW per stall, with the folding format introduced in Europe in June 2026 — live in France, Italy and Poland, and expected to roll out widely across the UK and Germany from Q3. Expressed as session time, that changes whether a mileage reward gets spent.
The model
Sessions = (miles ÷ mi/kWh) ÷ kWh per session. At 3.5 mi/kWh, 650 miles is about 186 kWh. The question is how that divides into stops.
| Stop type | kWh added | Stops to spend the reward |
|---|---|---|
| Short top-up | 20 | ≈ 10 |
| Ordinary stop | 35 | ≈ 6 |
| Road-trip stop | 50 | ≈ 4 |
Where the 500 kW figure actually lands
Not on the kWh you need — that is fixed by miles and efficiency — but on the minutes each stop costs. And peak rate is not average rate: charging tapers as state of charge rises, and the car's own maximum acceptance caps what any stall can deliver. Treat 500 kW as a cabinet headline and model your own car in the charge-time calculator.
Why session time is the binding constraint
Reward holders do not run out of appetite for free electricity; they run out of stops that fit into a week. A 40-minute stop is an errand, a 15-minute stop is a coffee. Halving session time is what converts "I should route via a Supercharger" into behaviour, and behaviour is what beats a six-month expiry.
The deadline the model exists to beat
Supercharging distance expires six months from the Grant Date — the day it appears on the account, not the order date. A 30-day warning email precedes it; there is no reissue and no transfer. Four to six stops across six months is trivially achievable and routinely forgotten.
The interaction with tariff
Faster stalls do not change what the reward displaces, which is decided by the price you avoid: 53p/kWh at a public rate against 7.5p/kWh overnight at home. Spending a reward on charging you would have done at home converts £98 of value into something closer to £14.
Where the model breaks down
At both ends of the state-of-charge range. Charging from 10% to 50% takes far less time per kWh than 80% to 95%, so a driver who habitually tops up from high states of charge will need more stops and more minutes for the same 186 kWh than the table implies. The practical version: spend a mileage reward on low-state-of-charge arrivals — long trips, in other words — rather than on convenience top-ups, and the session count falls toward the road-trip row rather than the short-top-up one.
The number to take away
Roughly 6 ordinary stops to spend the reward, inside six months, ideally on the most expensive charging you would otherwise have paid for. Everything else here is an input to that sentence.
Sources
Every figure above traces back to one of these. Terms and prices move — check the primary source before you rely on a number.
Tesla VoltBench is not affiliated with, endorsed by, or sponsored by Tesla, Inc. We report on the UK programme and run the numbers; we don't speak for Tesla. Where we link a referral link anywhere on this site it is marked rel="nofollow sponsored" and we may earn Tesla credits from it — see our referral disclosure.