Otways and Great Ocean Road trip – Day 1

On a quiet public holiday morning we hitched up the Little Guy to start our first long trip. We had carefully planned the two-day route from Adelaide to the Otways because fast-charging infrastructure off the main Adelaide to Melbourne highway route is non-existent. There are now EV fast chargers every 200 km or less between Adelaide and Melbourne, but there are none off the highway route. Overnight stays at caravan parks would be essential for our plans, because they provide for a 50% charge from a regular power point. We’ve made extensive use of Plugshare and A Better Route Planner (ABRP) to estimate where, and how long, we will need to charge.

For this trip we were uncertain what our power consumption of the Hyundai Kona EV would be with the Little Guy camper at highway speeds. Based on trips to the Fleurieu Peninsula south of Adelaide we estimated that the normal highway consumption of ~18 kWh/100km would increase to 25 kWh/100km with the trailer. This would reduce the range (from a 100% charge) from ~320 km to ~230 km. This should be enough to get from one fast charger to the next.

We planned to stay the first night at a caravan park in Dunkeld, south of the Grampians in Victoria, where we could do a top-up charge that would enable us to get to the Otways the next day. Fast charging would be needed at Tailem Bend, Keith and Horsham. But to do the 195 km trip between Keith and Horsham would need a 100% charge in Keith.

Cruising through the Adelaide Hills on the fresh morning we were initially quite delighted at getting better than expected economy. Maybe this wouldn’t be such a challenge after all!

Tailem Bend charging was great – lots of room for the trailer, and we were getting a charge rate of over 70 kW. This is amazing compared to our day-to-day charging from a regular power point giving around 2.3 kW (similar to an electric kettle)! We only needed an 80% charge to get to the next charger at Keith.

Driving from Tailem Bend to Keith, we found the average power consumption was much worse than earlier, and in fact far worse than we had planned for. This may have been due to a head wind, or a less wind-sheltered road. While this leg of the trip would be fine, we needed to know we could make the following 195 km leg. What to do? Try driving slower and annoy the other traffic? Try turning off air conditioning or cruise control? Doing this and dropping back to 95 km/h still seemed to be using too much power (around 29 kWh/100 km).

After a semi-trailer overtook us, we started slip-streaming (following closely behind the truck) as a way of reducing the air drag and headwind effects. We wouldn’t be so relaxed about doing this without the distance-sensing adaptive cruise control in the Kona. Gradually the average economy improved noticeably despite now travelling at 105 km/h with the truck. This was a great thing to find out, but one doesn’t simply find a truck to follow whenever you want one!

At the Keith charger, things were a little awkward, as the camper trailer stuck out a bit too far into the service road. So we decided to approach the charger from the side. Another Kona EV pulled up as we were getting into place, so we were glad we’d left space for them.

Charging went more slowly here, only 33 kW this time. It looked like we were in for a longer wait than expected, especially since we needed to charge to 100% to get to the Horsham charger. EV battery charging from 80% to 100% can take as long as from 10% to 80%, so an 80% charge is usually optimal (and better for battery life too). We were happy to stretch our legs and wandered off for an icecream at Henry & Rose cafe. Passing the row of Tesla chargers close by, we envisaged a future where these country towns were set up with rows of fast chargers, busy with travellers enjoying nearby cafes and parks. Just as we finished our icecreams, the Chargefox app indicated the car charging had stopped at 69% and the charger showed “Faulted”. Damn!

A brisk 10 minute walk back to the charger. Restart the charging. Wait. 80% charge and it stopped again. Would this charger even allow us to charge to the 100% we needed to get to Horsham? Restart the charging once again. Then at 89% another pause for a couple of minutes, but this was just the Kona battery check that monitors its battery condition. After restarting, the charging rate dropped slower and slower.

By the time we had a 93% charge, it was getting so late we changed our plans. We would arrive too late in the day at Dunkeld so decided to aim for Dimboola (nearly at Horsham). Again we were concerned about power consumption for a while, but after another stint of slip-streaming behind a truck, we were convinced this substantially improved our economy – enough that we could have even reached Horsham with our 93% charge. An additional fast charger at Bordertown or Nhill would make a big difference to this trip.

Dimboola is a lovely one-pub town a little off the main highway, and was a lovely spot for a stay and walk along the Wimmera River.

What did we learn on the trip over?

  • Highway speed power consumption was higher than we expected, 28 kWh/100 km
  • Allow more time for charging than ABRP suggests, especially if charging above 80%
  • Charging above the optimal 80% would be unnecessary with a few more fast chargers along the route
  • Chargers may have problems, or could be busy/unavailable when you want to use them
  • Slip-streaming noticeably reduces power consumption
  • Be flexible with plans

2 thoughts on “Otways and Great Ocean Road trip – Day 1

  1. Thanks for the blog, very interesting.

    Keep in mind that you are increasing the fuel consumption of the truck when you slipstream. Also, truck drivers don’t like cars following close behind, it’s a distraction and potentially a safety issue. Speaking as a truckie myself.


    Liked by 1 person

  2. Hi John,
    Thanks for your comments. It’s good to hear your perspective as a truckie! I should clarify that when we talk about slipstreaming, we are certainly not tailgating, and are not as crazy as this cyclist https://www.youtube.com/watch?v=rBC9pCEJ6o0. The benefit from slipstreaming would surely be greater if we followed closer, but we still manage to see a benefit while keeping a safe distance. Also, based on a range of reading, it seems very unlikely that this would increase the truck fuel consumption.
    We wonder if truckies (and other drivers) feel it’s more of a hazard to have a car driving at only 90 km/h on a one-lane highway, than following behind at the same speed.
    cheers, David

    Liked by 1 person

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