Charging an EV
Originally published on 18 May 2017.
There are two broad types of charging systems that are suitable for charging an EV, AC Charging and DC Charging .
GRN CAB (Nissan Leaf) being charged via AC - the port on the left is for DC charging.
This type of charging is most suitable for locations where drivers stop for longer or, where a high turnover of users is less important.
At the most basic level, you can plug your EV directly in to your household socket. For our Nissan Leafs, this takes around 10-12 hours for a full charge from near empty.
The next level up is a dedicated charger. For around $1000 (plus installation), you can get a faster AC charger installed. This cuts the charge time by more than 50% - for example, it only takes around 4 hours for our Leaf to be at full capacity, vs around 10 to 12 hours charging at a normal household outlet.
There are also AC systems available that can provide a higher-powered charge (up to 43kW) but you need a compatible vehicle to take advantage of this high charge rate.
The faster AC charger installed at our offices. From near empty to full in 4 hours!
DC powered charging in New Zealand is what we're referring to when we say "fast charge". These systems generally provide charging at a rate of up to 50kW (at this rate our Nissan Leaf would be charged to 80 percent full in around 20 minutes).
This type of charging is suited to locations serving inter-city EV drivers, where drivers want to make shorter stops, or where the infrastructure provider wants to encourage a rapid turnover of users. Usually this is charged (in monetary terms) by a combination of time and kW delivered.
Because EV’s charge slower for the last 20% of battery capacity, it is most economic to use these for a quick top up to 80% of capacity, where you are getting maximum charge rate and so minimising the time component of the charge.
Green Cabs are installing two 25kW chargers at Wellington airport for our EV fleet to use. At around $10,000 per charger, plus installation, these units are not economical for home use but they will ensure our EV fleet always have enough juice.
If you are lucky enough to drive a Tesla, then you have access to the ultimate fast charger. The first one opened recently in Hamilton with others planned for Sanson, Taupo and Auckland. Tesla supercharging stations charge with up to 145 kW of power distributed between two adjacent cars, with a maximum of 120 kW per car. That is up to 16 times as fast as public charging stations; they take about 20 minutes to charge to 50%, 40 minutes to charge to 80%, and 75 minutes to 100%.
A high speed DC charger!
Find out more below & stay tuned for our next update!
NZTA Guidance on Charging - https://nzta.govt.nz/planning-and-investment/planning/planning-for-electric-vehicles/national-guidance-for-public-electric-vehicle-charging-infrastructure/using-public-charging-infrastructure/charging-equipment/charging-point-connectors-and-socket-outlets/
ChargeNet - https://charge.net.nz/
Tesla Supercharger - https://www.tesla.com/en_NZ/supercharger