At the base of the Tasman Glacier global warming was happening right in front of us.

As I approach a curve in the highway, I lift my foot off the throttle. A row of green dots lights up on the dashboard and I allow myself a smug smile. My Britz electric camper van is recharging itself, converting speed back into battery juice.

It's a good thing too, as by the time I got to my first recharging opportunity there were only 10km left on my "remaining distance" dial, and the trouble with electricity is that you can't hitch-hike down the road with an empty can to get a bit more of the stuff.

As I lifted the weighty plug into the recharging socket I realised this was no longer road travel as we know it. This was going to be a strategic challenge, like keeping a sailing ship going while the wind holds, or nurturing a horse or a camel through the long gaps between haystack or oasis.

Travelling through Waipori Gorge. Photos: Peter Dowden I'm on a mission to see if freedom camper van travel can be carried out responsibly and with minimum impact on the environment. Tourism in general and camper vans in particular are getting plenty of negative comments lately as sheer numbers of even the tidiest tourists are crowding out and trampling New Zealand's favourite spots.

My home for the week: a very comfortable, fully-kitted-out Britz EV double-berth camper van, with toilet, shower, stove-top, microwave and fridge. Its New Zealand-made camper body was built over a Chinese-built LDV EV80 with a 56kWh battery. This vehicle normally has a range of 190km (with a half load on board) as a standard van but with the extra weight and wind drag of the camper rig I was advised to depend on only 120km between fills.

Normally, a camper van uses about twice as much fuel as a car, so by choosing electricity over liquid fuel I am all but eliminating one aspect of environmental impact. My other rule will be to only camp where legal, to follow all the rules and to leave each campsite a little tidier than when I arrived.

Charging at Lumsden's Four Square supermarket.

My first night was spent at Riversdale, in northern Southland, where camping for "self-contained" vans is allowed in the town centre. My surroundings are best described as municipal: it is a large quadrangle of gravel, shared with the town recycling bins.

Here the limitations of my vehicle first came to light. My van had an all-electric cooking and heating system, and the above-mentioned 56kWh battery should provide plenty of power for the tiny 1kW cooker and 500W microwave - but they were not interconnected. This is the pitfall of being an early adopter of new technology: by driving a prototype, my comfort and convenience were limited by the imaginations of the engineers who designed it. I hope Britz attends to this and comes up with a better system. Until then, if you want to go EV camping and need a hot meal and hot shower every day, you will need to plug in at a caravan park.

I had my dinner at the pub, where they had plenty of energy to cook it.

I spent most of the next day of my adventure recharging the van at Gore, Balclutha and Milton. Still getting the hang of it, I was exploring the fine line between almost running empty, as I had on my first day, and never doing anything fun by being too worried about the battery. Once I had my confidence I shunned the State Highway network and took a detour up the rugged Otago coast from Kaitangata to Taieri Mouth, on a well-maintained gravel road past wild landscapes and coastal hills. I headed inland to Waihola and after a last quick top-up I pulled up in darkness in the Waipori Gorge.

The Waipori River flows through New Zealand beech forest, the only patch of it on this coast between the Catlins and South Canterbury. In utter silence and darkness I listened to ruru hooting their plaintive requests for "more pork" and the rush of the river in full flow after a busy day's power generation upstream. In the morning my resolve to tidiness was tested: a beaten-up old couch lay in the middle of the campsite. As I contemplated how to get it in the van, a car whizzed past, horn honking furiously to meanly wake up any sleeping campers; this was only negative anti-camper sentiment I experienced. "I'm already awake," I shouted pointlessly at the receding speedster, "And you're probably the guy who dumped the couch."

Having become more confident about the camper's range, I shunned the State Highway network and took a detour up the rugged Otago coast from Kaitangata to Taieri Mouth. Photo: Getty Images

I stocked battery and larder in Dunedin and picked up my travelling companion. We charged in Hampden (kudos to local lines company Network Waitaki: they provide charging here for free) and ate fish and chips while we waited. Our overnight stay was at Duntroon, in a campsite straight out of New Zealand circa 1975: everything made of corrugated iron with exposed dwangs to hold your coffee cup, washing machine, ironing board and Domain Board. Importantly for us, a caravan plug allowed charging of the drive battery, the second means of charging other than the "fast chargers" I had used up to now. My on-board computer reported that about $10 worth of power took nine hours to load, so I slipped the Domain Board an extra fiver.

The Waitaki catchment is to electricity what Saudi Arabia is to oil, so it was an appropriate setting to road-test our e-camper. We juiced in Omarama (thanks again, Network Waitaki) but worked out that a planned visit to Aoraki National park would require an overnight charge at Glentanner, the closest caravan plug site to the park. This demonstrates a general problem with EV tourism: the chargers are not located at the Blue Pools, or Purakaunui Falls, or Taiaroa Head, rather they are at the Four Square, the New World or opposite the pub.

Governors Bush near Aoraki Mt Cook village.

To my great surprise, this grand tour of New Zealand's rural service towns was quite enjoyable and I never got as far as resenting the need to stop and charge regularly. Fatigue simply did not feature in this adventure, with such regular stops for rest and relaxation. Britz may have come up with a new form of tourism that leaves the holiday-maker genuinely rested, with human batteries fully recharged.

Aoraki is one of my favourite places, and an old traveller's trick is to stay overnight here as the weather is nearly always more conducive to mountain spotting in the mornings. We explored Governors Bush and Bowen Bush at Aoraki Mount Cook Village. The day had turned out a stunner and Aoraki was looking his finest. Our next stop was Tasman Glacier. I had heard of the newly-formed lake here and wanted to see it, so we headed up the Tasman Valley road.

We joined a coachload of other tourists at the car park and struggled up to the top of the terminal moraine. Here the view opened into vastness: the Tasman Glacier stretched into the distance. Below us a lake the colour of concrete was strewn with icebergs. Tourists looked out in awe and spoke in hushed tones. There was no whooping or high-fiving at the completion of this climb: global warming was happening right now in front of us. I heard someone say "It says here it's receding by 500 metres a year".

It was the day after the Christchurch mosque massacres, and the climate strike by school pupils, a day to think about why we were here, and what it was all about. I looked up to Aoraki and remembered Thomas Bracken's words in the national anthem: "May our mountains ever be, Freedom's ramparts on the sea ..."

At least we could say we had got here with minimal contribution to climate change, guided in the nations' van.

If you go

The Britz eVolve electric campervan is available for hire from Auckland and Queenstown depots. For the not-so-intrepid traveller, Britz provides hirers with carefully-curated itineraries between charging units installed at EV-friendly sites at holiday parks. These are set up with the ability to charge the vehicle and use the on-board appliances at the same time, giving the most efficient charging experience, reducing charging and range anxiety out on the road.

If you "go . . ."

... then expect to pay an extra $45. That’s the fee for having your on-board toilet tank emptied by the camper van hire company. A solution to the widely-alleged problem of fouling at New Zealand’s favourite scenic spots is proving elusive, but maybe the answer to the age-old question about what a bear does in the woods is "probably, but if you incentivise him to, then definitely". Hotels, motels, backpackers and camping grounds let you use toilets for free, included in the price. Camper van hirers should do the same.

Peter Dowden travelled courtesy of Britz.