Level 1 vs Level 2 Charging: Which One Do You Actually Need?
Level 1 plugs into any outlet and costs nothing. Level 2 is four times faster and needs an electrician. Here is how to tell which one fits your driving, in miles per day.
EV Charging Basics
Start here: how EV charging actually works at home — levels, kW vs kWh, AC vs DC, charging curves and the vocabulary you need before you buy anything.
Almost everything that feels impenetrable about EV charging comes from two units that look alike and mean different things. A kilowatt is a rate. A kilowatt-hour is a quantity. Charging speed, electricity bills, charger specifications and battery sizes are all one of those two, and once you can tell which, the rest is arithmetic you can do in your head.
The second thing worth knowing early is that your charging speed is never a single number. It is the lowest of three separate limits — the circuit, the charger and the car — and buying a bigger number for one of them does nothing if a different one is the bottleneck. This is the single most expensive misunderstanding in home charging, and it is the reason people fit 48 A wall boxes to cars that cannot accept 48 A.
Read these two before anything else on the site. Every cost calculation, every installation decision and every troubleshooting step assumes them.
kW vs kWh: The One Distinction That Explains Everything Else
Confusing power with energy is why charging specs feel impenetrable. Learn this once and charge times, electricity bills and charger specs all become arithmetic you can do.
Charging Basics: common questions
What is the difference between kW and kWh?
kW is a rate — how fast energy is moving right now. kWh is a quantity — how much energy moved in total. A 7 kW charger running for three hours delivers 21 kWh. Your bill is in kWh; your charging speed is in kW.
Do I actually need a Level 2 charger?
Not always. Level 1 on an ordinary outlet adds roughly 40 miles overnight, which covers the majority of daily driving. Level 2 matters if you drive more than that most days, or if you regularly need to recover a lot of range on short notice.
Why is my car charging slower than the charger is rated for?
Because the car is the limit. Every EV has an onboard AC charger with its own ceiling, often 7.2 or 7.7 kW. A wall box rated higher cannot push past it, so the extra capacity does nothing until you change the car.
Where should a complete beginner start?
With kW versus kWh, then Level 1 versus Level 2. Those two decide whether you need to spend anything at all, and they take about twenty minutes together.
Other topics
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