Frequently Asked Questions (FAQs)

Smart charging refers to the intelligent management of electric vehicle (EV) charging processes to optimise energy usage, grid stability, and user convenience. This technology enables EV charging stations to communicate with the grid, the EVs themselves, and sometimes with other smart devices, to adjust charging rates, schedules, and energy flows dynamically.

At Stevie we work with Monta to manage our smart charging. You can select your electricity tariff in the Smart Charging settings. This way, accurate off-peak charging sessions can be automatically selected and the costs shown (subject to full vehicle integration).  This not only allows you to use the greenest energy available, but also at the cheapest price.

The simplest way of explaining is that kWh (kilowatt-hour) is a measure of energy – it is similar to the litres used to fill up a petrol or diesel car. More kWh = more miles available.  This is how your electricity supplier will charge you for your electricity.  How many kWh you have used (how much you have filled up your car).  KW (kilowatt) is the measurement of power.  Essentially, it is the speed of your Stevie (i.e. 7.4KW).  The higher this number, the faster the charger is.

The charge cable of a tethered charge point is permanently attached to the unit. When you finish charging the unit, you simply coil the cable.

An untethered unit is supplied with a universal socket and can be used with any cable, including the cable supplied with your electric vehicle.

DSR stands for “Demand Side Response”. With using the Stevie App, we have a direct connection to all electricity network operators. DSR is important as with the huge increase in take up of EV’s, there is concern about energy demand on the electricity networks. With DSR, this allows the option of a possible delay to the charging session start (for example, after a power cut, a delayed restart will allow the electricity network to gradually restart rather than the sudden large demand from many Charge Points beginning at once). There is also the option of the electricity network limiting power supply to Stevie in order to not overload the network. This should not be a concern for using Stevie to charge your EV! We want everybody to be safe and have plenty of energy. It is purely to avoid possible power outages.

All Stevie’s are supplied with a CT clamp with a 5 meter cable. By attaching the CT clamp to your incoming electricity supply cabling (tails) the total property usage can be measured. Stevie can calculate the total power available and adjust the charging rate accordingly, so as not to overload the supply to the property.

YES! Like your phone charger and kettle can use the same 3-pin plug socket, the points and chargers only provide the power your car asks for.

In practice it depends on some fixed parameters and some variables. It’s basically:

Charger Power availability (some 150 kW chargers may only be plumbed for 50kW, for example) + Car charging speed capability (AC to DC on board charger speed if using AC, 400 volt or 800 volt battery architecture DC, etc.) + State of car charge (a 20% full battery will charge faster than a 80% full one) + temperatures (cold batteries don’t like charging fast, hot batteries throttle charging). 

Another important point when DC charging is that it’s like pumping up a tyre: the fuller the battery/tyre, the harder it is to get more charge/pressure in and the slower it gets.

At about 80-90% the charging rates slow down.  So the 50-150kW that you could have been pulling at 20% charge may have dropped to 20kW at 90%.

It’s therefore recommended and quicker that unless you really need the last 10-20% of a charge, then stop charging at about 80-90% and move on.

This depends on the car you buy as they’re often set up differently. Early Leafs used to have an ‘80%’ option and you only charged to 100% when intending to go on long journeys (100 miles in an early Leaf was a long journey).

But generally it’s found that early on in your EV learning journey:

– Charge when it’s convenient (such as using smart charging functions for overnight charging)

– Don’t keep ‘topping off’ when you’ve only driven a few miles, they’re happier left between 30%.

– Leave the car to look after its own battery, it’s programmed to.

Charging at home can be free or negative with solar and certain Octopus accounts, ~10p/kWh with overnight tariffs or ~30p/kWh on a standard tariff.

On the road, still a few free charging points, such as some 3/7/22kWh AC points. Some charge 30p a kWh for local 50kWh DCs and upwards of 60p/kWh for faster or more popular chargers, such as those found in services on and off the motorways.