This is one of those blog posts where I’d wondered something, looked it up, and am now sharing what I’ve found out. When it comes to charging your electric car, you may hear the terms ‘level 2’ or ‘level 3’ charger being used. They’re not common terms in the UK, but you may encounter them in other countries – especially the US.
Level 1 chargers
A level 1 charger is, essentially, just a standard 3 pin plug like you have at home. Your electric car will probably come with an adaptor cable, with a 3 pin plug on one end, and a Type 2 plug on the other end. There’s usually a chonky box on the cable, known as an EVSE (Electric Vehicle Supply Equipment), that regulates the power flow. Colloquially, these are known as granny chargers.
In the UK, our standard power supply is 240 volts and 13 amps. Going back to GCSE Science, we know that power is the product of voltage and current (amps), so the maximum output is 3.1 kW. An electrician may be able to fit a waterproof external plug socket for you which is rated at 16 amps, upping the maximum power output to 3.8 kW. One of our neighbours had this done for charging their plug-in hybrid as it was cheaper than a dedicated car charger (level 2, as we’ll encounter in a bit).
In the US, the voltage is lower (typically 120 volts) but the current can be as high as 20 amps, depending on how it’s been wired. However, even a 20 amp socket in the US can only output a maximum of 2.4 kW due to the lower voltage.
A level 1 charger is therefore going to charge your car quite slowly – especially if you have a big battery. I have also seen photos of plug sockets that have melted due to continual use for charging electric cars. And it’s (probably) the least efficient; some tests suggest that 25% of the electricity doesn’t make it into your car’s battery and is lost as heat.
Level 2 chargers
Level 2 chargers are the dedicated electric car chargers that you can get fitted at home. In our case, we have a Rolec EVO unit, and this will be fitted to the outside of your house. In the UK, it’ll have a Type 2 connector, and will be capable of much higher current – up to 32 amps. That equates to (almost) 7.7 kW, which is the maximum that you can get on a single-phase electrical supply that is standard in UK homes.
My Rolec charger lets me vary the current, so I can set it below 10 amps if I’m not in a hurry and want to make the most of my solar panels. Level 2 chargers also incorporate EVSE inside them, so the cables just tend to have a standard type 2 plug on each end.
Many public chargers are also level 2 – especially older ones. Some may be connected to a three-phase electrical supply, which triples the power output to 22 kW. You’ll generally find these at places where you can park your car all day.
I personally describe level 2 chargers as ‘medium’ speed, but a full charge at 7 kW will take a long time for larger vehicles. For our Nissan Leaf, a full charge (from 0 to 100%) would take 6 hours and 30 minutes, although that’s partly because it can only accept 6.6 kW from level 1 or 2 chargers.
Level 3 chargers
Level 3 chargers are the rapid and ultra-rapid chargers that can output 40 kW or more – some can do up to 150 kW. Unlike level 1 and 2, these chargers use DC (Direct Current) rather than the standard AC (Alternating Current) that you would get from a standard 3-pin plug. They also use different plugs – CCS2 is the most common, but some cars, like our Nissan Leaf, use a competing standard called CHAdeMO. You’ll also find that these are almost always ‘tethered’ chargers that include their own cable, so you won’t need to plug your own cable in.
I doubt you would be able to get a level 3 charger installed at home, as they’re expensive and would probably need planning permission and authorisation from the electricity distribution network operator (DNO). But increasing numbers of these rapid chargers are available when out and about, and especially at places like motorway service stations where you need to charge quickly whilst en-route somewhere.
How fast your car will charge will again depend on its maximum charging speed. Our Nissan Leaf, when using CHAdeMO, can only accept up to 46 kW. Still, that means a full charge in less than an hour.
DC chargers are also more efficient, in that you’re less likely to lose power as heat than AC chargers. As these chargers are generally the ones you pay a premium for, that’s a good thing as almost all the electricity you pay for will make it into your car’s battery. However, regular use of rapid chargers can degrade the battery more quickly.

