Charging away from home

Tesla Superchargers Explained

Last modified: 2020-12-22

6 min(s) read

What is a supercharger?

Simply it’s the fastest form of charging a Tesla, they’re owned by Tesla and cost on average 26p/kWh but each location slightly varies in the cost or free for selected owners (primarily older owners of Model S/X). The chargers cover a large chunk of the UK and Europe allowing you to move from one to another to your destination for most trips. When you plugin at home you will be using AC power (from the grid) this needs to be converted to DC power to enter your battery. Whilst charging at home your car performs this conversion using a single or dual charger module built into the car, a supercharger uses 12 of these charger modules, identical to the ones in your car, housed in an external cabinet to provide up to 250kW DC directly into your car battery, it bypasses the internal chargers in your car.

What speed can I realistically expect from a supercharger?

Tesla claims that you can refill a car from 10% – 80% charge in under 40 minutes, and that you can half-fill the car (i.e. reach 50% charge) in as little as 20 minutes. These are both achievable, but they represent the optimum outcome and there are various factors that affect speed.

What are the costs?

A charge costs ~£0.26 per kWh or free for selected owners (see below). To top up from empty to 100% in a 75D / Model 3 LR it would cost you ~£15-£20 but in reality, you probably won’t be arriving at a supercharger with an empty battery and won’t leave with 100% state of charge so this will be less. More details on this

How do I get free supercharging?

  • Get a referral code when ordering your Tesla, this should give you free supercharging miles (normally 1000)
  • Buy a used Tesla that has unlimited supercharging built in

How do I use a supercharger?

Enter the destination on the in-car navigation. Arrive & Plug in. It really is that simple. A green light will appear near the charge port and this shows you’re now charging. Keep an eye on the app to see how quickly the car is charging. Make sure you have a valid payment card on your account. When you’re finished go to the plug and press the button to release the cable from the car, now hang up the cable inside the charger and continue your trip.

Charger Pairs (e.g. 1A & 1B)

Image from Stein Ole Strand on

This only applies to super chargers with two cables attached (aka V2) Urinal etiquette at superchargers, basically superchargers are in pairs (e.g. 1A + 1B, 2A + 2B), a general rule of thumb is never plugin to a supercharger if another car is going to be immediately next to you. You will see stickers at the base of each supercharger showing their number and pair, if a car is plugged into 1A then don’t plugin to 1B if 2A or 2B is free. Priority is given to the first car that is plugged into a pair. If someone plugs into the pair you’re using your charge rate might be slightly reduced.

Why is a supercharger running slowly?


Remember a very cold or very hot battery or ambient temperature will affect the charging time and rate.

State of Charge (SoC)

The car can charge at a must higher charge rate when the battery is relatively empty compared to when it’s getting closer to full (80%+).

Charge Rate Tapering

A Tesla supercharger is capable of delivering up to 250kW of DC power to the battery pack, however, this is generally only when the battery has a fairly low SoC (under 25%), between 25%-80% the charge rate will slowly decrease in power but still give the fastest possible way to charge your car. At 80% SoC most of the time you will be ready to travel to your next supercharger or final destination, if you need to continue to charge above 80% you will see a dramatic reduction in the charger power. If there is another charger further along your route it is almost certainly preferable to stop charging, drive on, and stop a second time, rather than continuing to charge above 80%. Above 95% the rate of charge is slower than many home AC charge units.  And by 98% charge the rate is so low that it is almost certainly not worthwhile for you to wait for the last 2%.

What else could be slowing the charge rate?

Firstly, check you’re not using a paired supercharger (see above) that someone else is using. Secondly, try moving to another supercharger (e.g. if plugged into 6A, try 1B instead)

How do I know when I’ve got enough charge to continue my trip?

If you’re using the route guidance the navigation system will alert you when your car has enough charge to continue your trip. Remember if you’re arriving at a location that doesn’t have charging facilities you might need to charge more at the supercharger to ensure you’ve got enough charge to return.

What are Idle Fees?

All charger locations are for charging and that is it, you should never park or leave a car in a charging bay if your car isn’t charging. To combat this, owners campaigned Tesla to start charging people once they’ve finished charging and if they’ve left their car. Idle fees automatically occur when your car has finished charging and hasn’t been moved. A customer would never leave a car parked by the pump at a petrol station and the same thinking applies with Superchargers. Idle fees will accrue if the car is not moved within five minutes after the charge session is complete and the station is at least 50% full. For every additional minute, a car remains blocking a Supercharger bay, it will incur a £0.30 idle fee, e.g. 10 minutes overstay = £3 charge. The Tesla mobile app notifies you both when charging nears completion and again when fully done. Additional notifications will alert you when idle fees are incurred. Learn more about Idle Fees.

What if there is a problem?

It rarely happens but if a supercharger is out of order then try this:

  • Unplugging/replugging the connector
  • Try another charging stall
  • Rebooting the centre console (press and hold both steering wheel scroll wheels).
  • Report the issue to Tesla Roadside Assitance (number found on user manual inside the car)
  • Consider posting an update on the discussion group

Anything else I should know?

Tesla Charging Etiquette

The signposts at superchargers are easy to hit if you’re not concentrating

I’m still confused about something

Read this & then search the discussion groups

How much does a supercharger cost to install?

To be clear this is the cost for Tesla to install a supercharger bay. The prices vary from £80,000-£500,000+, in short, it depends dramatically on:

  • The current power in the area
  • Available locations
  • Paperwork and planning time
  • The amount of supercharger bays required
  • The plans for future expansion, e.g. 12 bays with enough power for a further 12 bays

Do you have the expertise? Share your knowledge!

Remember modifying your vehicle may invalidate part of your vehicle’s warranty.
Therefore, be careful and check with Tesla if unsure. Also any modifications will most likely need to be OK’d with your car insurance company.

To the best of our knowledge, these guides are correct and factual. However we take no responsibility if something does go wrong.

If you spot a mistake please ensure you alert us.