UK Off Roading ›› 4x4 SUV ›› Electric Cars ›› kW and kWh Explained
If you're thinking about buying an electric car it's good to understand the main difference between kW (kilowatts) and kWh (kilowatt-hours).
The information in this section explains what these values mean and how one is a measurement of power and the other is a measurement of stored energy.
Most of our electric car reviews for UK drivers quote measurements as kW and kWh. But what do these different values mean and why are they so important for EV buyers?
In simple terms...
The first thing to learn is that kW stands for kilowatts, whereas kWh is an abbreviation of kilowatt-hours. Despite being similar, the two units of measurement do not refer to the exact same values.
Think of it like this, kW measures power (e.g. output of a motor or the energy used to charge it). Typical outputs for modern electric vehicles are 7kW, 22kW, 50kW, and 350kW.
Put another way:
It refers to the rate at which power transfers into an EV from a charging station (e.g. the charging speed). Thus, using a rapid charger (also called DC fast chargers) is faster because a 100kW input is going to recharge a battery quicker than a 50kW charge.
But, not all electric cars are powerful enough to handle these rapid chargers. Moreover, some EV batteries respond better than others to regular rapid charging.
According to the official auto manufacturers, these three electric vehicles (EVs) can handle 350kW charging:
Pro Tip: Another section spotlights some of the new electric car models coming soon - many of which will be for sale in the United Kingdom.
In an electric car, kWh refers to the total measurement or capacity of electrical energy stored in the battery - or used by it. In fact, UK energy providers use a similar metric when they bill you for domestic electricity usage.
For example...
The 2025 Renault 5 E-Tech Electric Iconic Five has two versions of battery capacity, that being 40kWh and 52kWh.
So, all other things being the same, the larger 52 kWh battery capacity means you can travel further (the range) after a single charge.
Here's a few more examples of different battery sizes (storage capacities) and how it relates to the distance it can travel (e.g. the associated range):
If your electric vehicle has an 80kW electric motor with an 80kWh battery and you run the motor continuously at maximum speed, the battery would completely drain after exactly one (1) hour.
Our review of the Adventure 1 from Potential Motors outlines the compact off-road recreational vehicle and explains how the mini EV explores land beyond the highways.