The best way to power homes with electric vehicles

Electric vehicles (EVs) are a great way to save money on filling up, plus reduce your carbon dioxide use. The Energy Efficiency and Conservation Authority calculates that you can charge up your EV for the equivalent of 30c per litre. Each EV uses seven to 10 times less fossil fuels than a petrol or diesel car over its lifetime, according to Ecotricity.

In New Zealand, electric vehicles are growing in popularity as the technology becomes more readily available. There are now 11,300 EV and hybrid electric vehicles in the country, with the numbers almost doubling in a year, according to the latest figures from the Ministry of Transport.

But having an EV or a plug-in hybrid EV does mean you use more power at home to charge your vehicle, which is often done overnight. Fortunately, a number of power companies offer special deals for EV owners and it pays to look around for the best charging option and the best power plan to suit your needs.

How to charge your electric vehicle

Electric Vehicle Charging

Before you decide on which electricity retailer to use, it pays to set out how you will charge your car, as there are a range of different ways to charge-up.

Standard wall socket

With a standard three-pin charging cable, you can plug a car right into a standard household power point, which will be available in most garages. This does have limitations, however, as it is the slowest way to charge, taking approximately 10-18 hours to charge 100km of range. To extend your battery life, you may have to use a timer on your cable to avoid charging your car to full every night. It is also important to only use the charging cables that came with your vehicle, and don’t use extension cables, adapters or multi-boards.

Caravan/industrial plug

Some cables come with an industrial or caravan plug, allowing for faster charging than a standard wall socket. These are the kind of socket you’ll typically find for caravans or mobile homes in campgrounds, and they are sometimes called “blue commando” or industrial sockets. A registered electrician will be needed to install a special wall power point to allow this to be used. While these chargers are faster than a standard wall socket, this is still a form of slow charging. It takes about five to six hours to charge 100km or range. Again, you may have to use a timer to avoid charging your car to full, and you should not use extension cables or adapters.

Dedicated charging units

A dedicated wall-mounted charging unit is recommended to have installed at home, with the work to be done by a registered electrician. These are increasingly common and convenient as they charge faster than using a standard wall socket. There are a wide range of dedicated charging units, with higher-end devices able to display information and enable you to control charging using your smartphone. Dedicated charging units usually offer a medium to fast charge, with the time depending on which charger is being used as well as which type of car:

  • A single-phase charger takes about three to six hours to charge 100km of range.
  • A three-phase charger takes under an hour to charge 100km of range.
  • A DC charger takes 10-25 minutes to charge 100km of range.

Fast/rapid chargers

There are now about 100 public rapid chargers nationwide, with the number growing all the time. Rapid chargers allow EVs to be charged on the move and are often installed at shops and supermarkets so you can fill up the cupboard at the same time. Rapid chargers take about 20 minutes to charge a battery to 80% full. However, to extend the life of your battery, it is recommended to use rapid chargers only occasionally, such as when travelling away from home.

Which electricity retailers offer EV charging plans?

If you have decided to use an electric vehicle, there are a number of NZ power companies which offer special electric vehicle plans. This means it will not cost you the earth to charge your EV or plug-in hybrid EV at home:


Mercury Energy offers an electric vehicle plan, called the EV Fuel Package. The offer is for a 20% discount off all electricity used by the home overnight, between 9pm and 7am. Outside of these times, Mercury’s standard rates apply. The package applies to all new or existing customers who own or have a long-term lease on a plug-in vehicle. The plan can also apply to a bach, if you have one. Customers must sign up for at least two years though, and have a smart meter – or allow one to be installed. Mercury is a member of EV100, an initiative to help reduce carbon emissions and drive electric transport. It also has an online calculator, which helps you calculate fuel savings for popular electric vehicles, based on the distance you would drive it.

Meridian Energy

Meridian Energy offers an Electric Car Plan available for any residential customer who own a plug-in electric car. The plan has special low night rates between 9pm and 7am, although these are off-set by higher day rates, like a normal Night Tariff. Customers must sign up to a two or three-year term to get Meridian’s special rates and a smart meter is also required. The plan can also include special offers, such as a $300 credit to cover the cost of charging your EV for a year. For EV customers using power during the day who are not keen on a day/night plan, Meridian says it can arrange a suitable plan.

Nova Energy

Nova Energy offers a Home EV Electricity Plan to residential customers who own, lease or have access to the regular use of an electric vehicle. It allows customers to charge their EV at home at any time, and rewards them with a 20% prompt payment discount instead of Nova’s usual 15%. The discount is only valid for customers who pay in full, on time, using e-Billing and expires at the end of July 2020. There are no fixed terms for the contract and prices are subject to change.


For customers with an electric vehicle, Powershop will “hook you up with cheap off-peak charging rates”. Powershop does not specify what these rates are but says it is available in most areas, including the main centres, allowing people to charge their EV, e-bike or e-scooter for less.

Flick Electric

Flick Electric does not have a specific electric vehicle plan but it charges spot prices or wholesale power prices. For EV owners, this means they can charge their vehicles when prices are at their lowest, usually at night.

Tips and tricks for extending your EV battery life

Also Electric Vehicle Charging

No matter what electricity retailer you are with, it is important to take care to maximise your EV battery life. EV batteries can degrade slowly over time, meaning that the distance (range) the EV can travel gradually reduces. Here are some simple tips and tricks to reduce degradation:

  • Avoid charging to 100% every day. A fully charged battery is under greater stress than a partially charged battery, so it is better to charge to 60-80%. Use software or timers on the charger to avoid fully charging.
  • Minimise running your EV when the battery is below 20%. If you have 20% capacity, it is time to charge-up.
  • Avoid aggressive driving, such as hard braking and accelerating. This is especially important if your battery level is low.
  • Charge at home and use fast charging only where necessary.
  • Avoid extreme hot or cold temperatures. In summer, try to park in the shade or under cover. In winter in places where it snows, plug in as often as you can to take advantage of your EV’s battery thermal management systems.
  • Take care if storing for a month or more. Ensure the vehicle won’t get too hot or too cold. Use the “storage” charging mode if you have one and keep it plugged in. Store the battery about 60% full and apply a refresher charge before it drops below 20%. Never let your EV sit idle for more than three months.
  • Have a regular service by a qualified service provider.

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