Nigel Ramsay

Software Engineer from Wellington, New Zealand

Traveling to Palmy in an Electric Vehicle

18 May 2019

We drive our red Nissan Leaf from Wellington to Palmerston North for a weekend trip away.

EV driving range

Our car has a maximum range of about 150 km before the battery needs a top-up. The journey from Wellington to Palmerston North is 140 km.

There are a number of factors that can affect your actual range. These include:

  1. Hills — as you can see in the chart above, there are some significant hills on the drive to Palmy. An EV will actually recharge the battery when you’re driving down a hill, but it’s not a 100% return of energy, as wheel friction and wind resistance still need to be overcome.
  2. Weight — having a heavy load, or a full car of people does consume more energy than a single driver in an empty car.
  3. Average speed — like all vehicles, driving fast (over 100 km/h) makes serious dent in the fuel tank or battery. Keeping the speed at or below 100 km/h is great for both safety and economy.
  4. Weather — a wet road, or head wind will make a minor dent in the range.

In our drive to Palmy, we have a full car travelling at normal speeds (up to 100) in dry/still conditions. As a result, we’ve chosen to top up the battery along the way. We might be able to get there on a single charge, but there’s no point in the unnecessary risk of running out.

Charging on Otaki

There are several places to charge along the way.

Charging locations near Wellington (green icon). Under construction (yellow icon) Charging locations near Wellington (green icon). Under construction (yellow icon)

We want to pick somewhere that is at least halfway into the journey. Otaki is the natural place for us to stop, as it’s enroute and there is good shopping there. If the charger is occupied, we can continue on to Levin and top-up there instead.

The fast charger at New World in Otaki The fast charger at New World in Otaki

We really don’t need much energy — around 5 kWh will be enough. The ChargeNet network fees are 25c per minute plus 25x per kWh, so our bill is around $3 for nearly 7 minutes of charge.

ChargeNet transaction ChargeNet transaction

After the short break, we are back on the road with 65% charge level, and an estimated range of 115 km. This is more than enough for the expected 68 km of driving.

We arrive 45 minutes later with 25% battery remaining. Maybe we could have made it on a single charge after all.

Charging at the in-laws

The cheapest place to charge your car is at someone else’s house. Luckily for all involved, it doesn’t cost much at all. To fill the battery from 25% to full is about $3.90 on regular electricity rates (20c/unit).

We have an adapter cable that lets us plug in to a home power socket. It charges very slowly, so we leave it plugged in overnight.

Orange adapter cable Orange adapter cable

Convenience

The trip to Palmy is the longest we’ve been on. A short stop in Otaki is really no problem.

We have longer journeys planned for later in the year, with destinations such as Turangi, and another to Hawke’s Bay. We will need multiple top-ups, with much higher charge levels, at each stop.

I suspect it will add an hour to our travel time, which will be inconvenient. But the benefits of cheaper travel and not contributing to the climate crisis outweigh these costs.