Anyone looking at electric cars for the first time encounters a lot of numbers of varying importance, rarely well explained. A few relationships that describe daily reality far better than the brochure figures.
Maximum charging power hardly matters
Manufacturers advertise peak values — 150 kW, 250 kW, more. That figure is reached only briefly and says little about actual charging time.
What matters is the charging curve: how power varies with state of charge. The battery accepts most power at low charge, and from around 60 to 70 percent the battery management system throttles considerably to protect the cells.
The result: 10 to 60 percent goes very quickly. From 80 to 100 often takes longer than the entire first half.
Practical consequence for long journeys: two short stops from 10 to 60 percent are usually faster than one long stop to 100. That's the most important behavioural change compared with refuelling, and the one that saves the most time.
Why battery temperature matters so much
The factor behind most winter disappointments.
Lithium-ion cells only accept charge quickly within a certain temperature window, roughly between 20 and 40 degrees. A cold battery charges considerably slower, sometimes at a fraction of the possible rate.
That's why many vehicles have preconditioning: enter a rapid charger as a destination in the navigation system and the car heats the battery on the way.
Anyone who doesn't use this and arrives at a charger in winter with a cold battery is surprised by the charging time. It's one of the few situations where using the navigation genuinely pays, even on a route you know.
Consumption is the relevant figure
Range is a misleading number because it depends heavily on driving style, temperature and speed. Consumption is the more stable measure.
Rough orientation: a compact EV sits at roughly 15 to 18 kWh per 100 kilometres in mixed use, larger vehicles considerably above.
Two effects surprise many people.
Speed matters disproportionately. Aerodynamic drag rises with the square of speed and the power required with the cube. The difference between 120 and 150 km/h on a motorway is substantial — more pronounced than in a combustion car, because EVs gain in city driving through regeneration and lose that advantage at high speed.
Cold costs twice. Once because battery chemistry delivers less capacity at low temperatures, and once because heating requires energy. A combustion engine heats using waste heat; an EV has little and must spend energy on it. Heat pumps reduce this considerably and are a sensible option in cold climates.
AC and DC
A distinction that causes frequent confusion.
At home and at most public charging points you charge with alternating current. The onboard charger in the car converts it, and its power is limited — often 11 kW, sometimes 22. A 22 kW post is no use if the car only accepts 11.
At rapid chargers, direct current is delivered straight to the battery. Here the battery and its management set the limit, not the onboard charger.
Practically that means: for home and overnight charging the AC figure is relevant, on the road the DC capability. They're two entirely separate numbers.
What damages the battery
Everyday recommendations are fairly consistent.
Sitting at very high or very low charge for extended periods stresses the cells. The common recommendation is to stay between roughly 20 and 80 percent day to day and charge fully only before longer trips.
Frequent rapid charging generates more heat and contributes to ageing, though less dramatically than once feared. Fleet studies suggest modern battery management handles it reasonably.
High temperatures while parked are unfavourable. A car sitting fully charged in direct sun for weeks in summer is the worst case.
For lithium iron phosphate cells, increasingly common, some rules differ — regular full charging is often recommended there, partly to recalibrate the state-of-charge display. Checking the manual genuinely pays here.
What I wish I'd known first
A note on home charging hardware, because it is the decision with the largest effect on daily convenience and the one people research least.
A standard domestic socket delivers very little — often only a few kilowatts, which can mean well over a day for a full charge on a larger battery. It works as a backstop and it is not a plan.
A dedicated wall unit changes the picture entirely. Even a modest one handles overnight charging comfortably for typical daily distances, which is the entire use case. Beyond a certain point, higher home charging power buys almost nothing, because the car is parked for eight hours anyway and the limit is the onboard charger.
What does matter is whether the unit can be scheduled or controlled, so charging happens during cheaper tariff periods, and whether the household supply can support it alongside everything else. That second point is where installations get expensive, and it is worth establishing before choosing a car rather than after.
That daily life is 90 percent charging at home or at work, and rapid charging is the exception. The whole public debate about charging infrastructure concerns the rare cases, not normal operation.
And that price differences for public charging are enormous depending on provider and tariff. Charging ad hoc without a contract can cost several times as much. That's where most people lose money in their first year, and it has nothing to do with technology.