FAQs
*Read the latest OZEV report?
OZEV (Office for Zero Emissions Vehicles) contracted Cenex to deliver technical audits of charge points from 2020-2021 . These audits took place over a three-month period between 24th November 2020 and 28th February 2021.
You can Read or Download the audit results here 📄PDF
What is the OZEV Grant criteria?
Why can’t I just use the three-pin house plug device that comes free with the car? It’s the same electricity?
According to Car Magazine “Most manufacturers recommend three-pin charging as a last resort only. Some sockets aren’t rated for long periods of continuous heavy usage – especially if you’re thinking of using an extension cable. Best to use a 3-pin charger as an emergency option, or if you’re visiting somewhere without its own charger.
As a result, manufacturers are increasingly refusing to supply three-pin chargers as standard equipment”.
In addition to the safety aspect there is the impractically long charge times as it is such a slow rate of charge. A Kia Nero will take around 30 hours to charge and for cars with large batteries like a Tesla or Porsche “forget it”.
Three pin chargers supply at around 2.5kWh verses around 7kWh for a fast domestic EV charger.
What’s the fastest charger I can have?
There are 2 types of charger, alternating current (AC) and Direct current (DC). The most powerful single phase AC charger (on a typical 240v 32amp supply) produces around 7.2kWh. This does rise with increased amps eg. 32amp can produce 7.7kWh- a 40 amp supply can produce 9.6kWh and a 48amp up to 11.5kWh. Direct Current (DC) goes through a transformer and produces higher charge rates.
Almost all domestic supplies, and many office/ light commercial supplies are 32 amp AC supplies. The most powerful charger (currently) available (on the 32 amp system) is around 7kWh.
Basic and generalised science.
Electric Vehicles charge with DC. It is the job of the on-board-computer (OBC) to identify and convert AC into DC. That is (partly) why DC chargers are ‘fast and ultra-fast or rapid’ as there is no conversion.
It should be noted that a car can only receive charge at a rate it is designed to receive this is known as the charging capacity. This rate is managed by its on-board-computer (OBC). Most cars can receive between 3.7- 7.5kWh from an AC charger and only some cars can receive more from a DC charger. Putting a Kia e-Nero on an ultra-fast 150kWh DC charger will not be any faster to charge than charging on a 7.5kWh home charger because that is the maximum charging capacity, whereas putting a Jaguar I-Pace will reduce charge time from 13 hours to 2 hours as its maximum charging capacity is 50kWh and the OBC will identify the DC and permit that faster rate of charge. However, the Jaguar will also work perfectly on a 7.2kwh AC charger. The Porsche Taycan is a current market leader with a charging capacity of 270kWh but again works fine on a 7.5kWh charger.
I want to charge two cars at once what’s the best system?
Twin sockets divide the kWh, ergo, if you have a twin socket 7.5kWh charger with two cars charging they will charge at 3.25kWh each. If only one car is charging it will receive the full 7.5kWh. DC chargers can split the higher Kw input, therefore have more sockets producing higher charge, so if it had a DC input of 150kWh technically it could run 10 sockets at 15kWh or 2 at 75kWh and so on.
In fact most rapid DC chargers have a fast charge ‘gun’ (or up to 4 guns) and a separate AC socket or gun so two cars get the optimum charge eg. The Taycan can charge at 150kWh on the DC gun and a e-Nero can take its maximum charge (7.5kWh) on the AC gun.
I want the charger to pay for itself, how does that work?
Owners can offer ‘Free to charge’, ‘Free for authorised users’ and ‘Pay to use’ EV chargers.
Free to use does exactly what it says on the tin, anyone can drive up, plug in, charge up and then leave.
Free for authorised users allows the charger owner to set up the system to allow some people (staff for example) free to charge and others (visitors) will have to pay, normally by smart phone app.
Pay to use allows the owner (landlord/ person who paid for it), the opportunity to earn money from users.
Pay to use - The money.
Typically, 1kW is charged at around £0.15p from your electricity supplier. The charger owner can legally charge whatever he wants for electricity. Normal pay to charge is anything from £0.35 kW up to over £1.00 kW, which the owner receives.
Ergo, an owner can (@£0.35p charge) make around £0.20p/ kW. On a 7.2kWh charger that equates to 7.2 x £0.20 = £1.44/ hour. On a 4 hour stay that again equates £5.76 and so on. The workings are the same so if you charge £1.00/kW the owner would net £24.48 over 4 hours. The payments are usually made through a smart phone App or Q code.
Many retail businesses use free to charge to attract users/ customers by advertising or publicly listing on a charger website a ‘free to use’ charger, thus attracting drivers to the venue.
Offices may use authorised to use to allow some people free charging but not all people.
The charge to use is usually adopted as it helps offset the initial costs of the charger and can actually make the charger a profit centre.
How long should customers be on a chargers to make it worthwhile?
This is known as dwell time. A full charge up from 0-100% is actually rarely needed. Normal journeys are well catered for as the increasing range of EV’s invariably means that non-home charging is often just to top up when convenient to extend the range. Any dwell time over an hour with an AC fast charger could add 20-50 miles range, which is more than the average total distance travelled during a days driving (20miles/ day *Nimblefins.co.uk)
Some chargers advertise AC & DC facilities, how come?
This refers to the ability to receive either, rather than supply both. This is potentially a benefit as supplies can be upgraded and charger and EV technology is fast moving. Even smaller budget cars are starting to have greater charging capacity so pre-planning or ‘future proofing’ is well advised.
Why do people have more powerful chargers than their cars can take?
Currently only a few cars can receive 22kW. However, EV technology is progressing very fast so getting a charger that can charge at 22kW is likely to be suitable in the near future.
How do I know if I will get a government grant?
There are certain criteria which need to be met in order to qualify for either a domestic (EVHCS) or workplace charge scheme (WCS). The domestic details can be found HERE and WCS criteria HERE
There are only certain chargers that are eligible to receive OZEV grants and only OZEV approved installers can apply for any grants.
Any grant application can be applied for by the OZEV approved installer and deducted from your total installation cost.
Can I claim the OVEZ grant for a company vehicle?
Yes, as long as you are assigned the electric vehicle for a minimum of 6 months.
How much does it cost to charge an electric vehicle?
As noted the figures vary between electricity suppliers and charge to use options. The quick calculator is to take the size of the battery and multiply by the charge/ kW from the supplier.
On the earlier example an e-Nero has a 39kw battery and using the home electric cost of £0.15/kW would make the total cost of 39 x .15 = £5.85. The same from a pay as you go charger (@£0.35p) would be 39 x .35 = £13.65
Can you overcharge an electric vehicle?
No, the OBC manages all aspects of charging to stop any overheating, charging or discharges.
What other financial incentives or benefits to having a charger installed?
There are many additional benefits attached to switching to electric vehicles including:
Reduced fuel costs
Showing your company’s green credentials
Generous government grants - up to £14,000.00
Super deduction on capital allowances - up to 130%
Improving your company’s ISO ratings
Saving employees BIK tax
Zero rated car tax and reduced VAT bill on electricity