Each month, we are seeing a remarkable increase in the number of battery electric vehicles (BEVs) being registered in New Zealand, and with the new Clean Car Discount scheme announced, BEVs are more appealing than ever before.

While demand is steadily increasing, many motorists are still unfamiliar with the technology, including the batteries used to power them.

It is important to understand the three main aspects of this a BEV battery: its capacity, charging capability and range. 

Capacity

An EV’s battery size is rated in kilowatt hours (kWh) - A kilowatt hour is a measure of energy used by an appliance/ BEV if it were kept running for one hour. So the more kWh the battery capacity has, the longer the vehicle range.

For example, a 2021 Nissan Leaf has a 40kWh battery and an approximate range of 270km, whereas a 2021 Hyundai Kona Elite Series II EV has a range of around 484km thanks to its larger 64kWh battery.

Essentially, the larger the capacity, the bigger the price, and the further you are able to travel on a single charge. This shouldn’t be confused with the power rating of the actual electric motor which is measured in kilowatts (kW). The power of the motor is what produces the impressive torque demonstrated by BEVs.

Charging

There are currently three main methods for charging a BEV battery available in NZ. Depending on your needs and the capacity of the BEV you choose, you may need to install the infrastructure to charge your vehicle at home. Sometimes, manufacturers include this in the price of the BEV, like Mazda who is offering early adopters of the new MX-30 will be treated to a free fast charge AC Wallbox Pulsar Plus.

1. Home (via an In-Cable Control Box (ICCB) charging cable)

This is designed to connect to a standard three-pin wall socket. This is a slow overnight charging method and will fully recharge a used Nissan Leaf in 6-8 hours, or a new Hyundai Kona Elite Series II EV in around 28 hours. The power supply from this cable is typically 10amp/2.4kW.

2. Home (via a Fast Charge Wall Box)

This is an optional wall box for your household and improves charge times by utilising a 16-32Amp, 3.7-22kW power supply. It can significantly reduce charging time at home but can sometimes cost over $3,000 to purchase and install. This needs to be installed by a professional registered electrician and should compliant with New Zealand regulations.

3. Public Rapid Charging Stations

This is the fastest way to charge a BEV, and can take up to 75 minutes to charge a large capacity BEV from 0% to 80%, typically utilising 25-50kW DC charging.

Finding a rapid charger is easy in some BEVs, but this isn’t the case in some used models. There are websites such as ChargeNet that can aid you in finding you nearest charge station.

Another interesting add on is planned and under construction there is currently one in the North island and two in the South Island that are under Construction. You can also filter your charging site depending on charge method ie CHAdeMO, CCS or Type 2AC.

The AA also provides a facility to locate Charge Stations through its time and distance calculator - aa.co.nz/travel/time-and-distance-calculator

In Wellington, the AA has introduced a mobile breakdown van fitted with a lightweight BEV charger to support AA Members who are caught short on their journeys. In 20-25 minutes it enables enough charge to drive up to 10 kilometres so Members can get home or to a nearby charging station. If the Wellington trial is successful, the AA will look at expanding the service to other parts of the country. 

Range

Two common terms you might hear when shopping for used BEVs are ‘state of charge’ (SoC) and ‘state of health’ (SOH).

State of charge (SoC)

State of charge is defined as the available capacity in ampere hours (Ah) and expressed as a percentage of its rated capacity. State of health represents a measure of the battery’s ability to store and deliver electrical energy, compared to a new battery.

State of Health (SoH)

State of Health is a useful way to judge how much life a used BEV’s battery has remaining. It gives an overall condition of a battery, not its current charge. For some vehicles, on-board diagnostics may provide data that will help you determine how much longer you can expect it to last based on how it has been used so far. For example, the Nissan Leaf displays how many bars the car will charge to out of a possible 12.

When buying a used BEV, it’s important to remember that SOH is often more useful that the mileage travelled alone. Remember - even a low mileage BEV can have a poor SOH rating.

Like with a smartphone, overtime an aging BEV battery can reduce in ability to store charge while the demand from the motor’s power remains the same. This means that a full battery charge won’t last as long.

New BEVs tend to have a fairly extensive warranty which covers the battery. This is typically between five and eight years from new or a set distance (e.g. 150,000km). The most affordable BEV in NZ - the MG ZS EV – offers an eight-year/160,000km battery warranty.

Can BEV batteries have a second life?

When a BEV battery no longer provides a usable driving range, it may be possible to have it either refurbished or replaced.

In some instances, it might be possible to just replace the dead cells within a battery. If a full replacement is required, you may be able to improve the range of your BEV by installing a new battery with more capacity providing it’s compatible with your vehicle - this had been the case with some Nissan Leafs.

Used batteries still have value. They may be refurbished, repurposed or recycled for uses like storing electricity from solar panels at home.

The AA is on the Governance group of the Battery Industry Group (B.I.G) together with EECA and Vector. B.I.G. is a collaboration between over 170 businesses and individuals across energy, waste, transport and battery sectors tasked with designing a solution for reusing and recycling large batteries commonly found in BEVs or stationary energy storage.

In May 2021, B.I.G submitted a proposed product stewardship scheme for large batteries to the Ministry for the Environment.

For more information on B.I.G and sustainability within the AA, visit aa.co.nz/sustainability.