Our solar equipped RVs – all proved a major success

Feb 25, 2019

Updated 2020

Solar Equipped RVs

We personally drove our solar equipped RVs some 170,000 km over most of Australia’s inland dirt tracks. Nothing failed in that distance (and 20 years).

Our solar equipped RVs – VW Kombi

Of our solar-equipped RVs, the first was a now rare 1971 VW Kombi Westfalia camper that we modified for extensive Australia dirt road usage. Solar back then was very costly. Our single Solarex 80 watt solar module cost $560 (a lot of money back then). This was far than I now advise, but it worked well as we travelled in areas of ample, reliable sun. A basic solar regulator controlled solar input to a 100 amp-hour battery. The battery could also charge, via a voltage sensing relay, from the VW’s alternator.

Kombi tilted module
The trustworthy VW Kombi and my wife (Maarit) just off the Strzelecki track – camping overnight. Pic: rvbooks.com.au

This system powered a 40 watt Engel chest fridge, plus internal and external lighting via three 20 watt halogen globes. Only two were used simultaneously.

The Kombi proved 100% reliable over some 25,000 km of mostly corrugated dirt tracks. These included the Birdsville, Oodnadatta and Strzelecki. Its low-slung engine, however, precluded deep water crossings. Further, a Kombi is all but impossible to keep in a straight line on soft mud tracks. I sold it a few years later and bought an OKA ex-mining truck.

Our solar equipped RVs – the OKA

OKAs are Australian-made 5.5 tonne 4WD trucks originally intended for use on mining sites etc. They are ideal for seriously fully off-road use. Some 550 or so were made from 1993 to 2010. Production then ceased. They are now sought after as stunning go-anywhere vehicles. Even after several hundred thousand kilometres, they now sell for well over their original new price! Ours was a 14-seat coach-bodied version made in 1994.

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The OKA crosses Wenlock river on the track to the tip of Cape York. The white dome is the antenna for its satellite phone. Pic: rvbooks.com.au

The original heavy steel roof was replaced the roof by a fibreglass pop-top. The interior was stripped to accommodate a dinette/double bed plus kitchen. The entire powder-coated white aluminium interior weighed under 75 kg (165 lb). Also installed were twin 220-litre water tanks, two 210 litre fuel tanks, a second spare wheel and a firewood rack.

The alternator was replaced by a Bosch 140 amp unit. This charged the 400 amp battery bank via an early smart alternator regulator and voltage sensing relay. I mounted two 100 watt Solarex solar panels on the cab roof, and installed a Plasmatronic PL20 regulator.

Main loads were a 71-litre eutectic Oz Fridge and a Westinghouse satellite phone/fax. The latter was as big as a large suitcase. It weighed over 15 kg (33 lb). Its dome antenna can be seen (above). I also installed 12 (switchable) halogen globes, each of 10 or 20 watts (this was before the era of LEDs).

Our solar equipped RVs – the OKA in use

We used the OKA extensively, driving across Australia (via Alice Springs) from our then Broome home (All Solar House) to the east coast and back. We did the return trip (about 13,000 km) twelve times in the OKA. And three more times with our later-owned 4.2-litre turbo-diesel Nissan Patrol and TVan. Some 80% of each trip was off-road.

The Westinghouse satellite fax/telephone was 100% reliable – but energy-hungry. I replaced it in 2002 by a hand-held version. This reduced energy draw, enabling us to slash battery capacity to 120 amp-hours.

Whilst ideal for long distances off-road, OKAs are too large and unwieldy for everyday use. We reluctantly sold it to a Queenslander – who drove it home. He later restored it superbly.

How the previously-owned OKA looks now.

Our solar equipped RVs – Nissan Patrol/TVan

We replaced the OKA by one of the last 4.2 litres TD Nissan Patrols, and a TVan.

This time I went all solar. I designed and installed a self-contained system in each. The Nissan’s two 100 watt solar modules charged a 110 amp-hour AGM via a Plasmatronic PL 40 regulator. The alternator did not normally charge that battery. If needed it could be done via a switched voltage-sensing relay. Its main load is a 60 litre Engel fridge. It also powered a single outside light.

Solar TVAN and Nissan Mitchell Falls

The Nissan Patrol and TVan at Mitchells Falls (in Australia’s far-north Kimberley). Pic: rvbooks.com.au

The Nissan also had the very first Redarc BMS 1215 Battery Management System (for which I assisted Redarc to formulate the original specifications). This, (unit 0000001) was powered from solar and the Nissan’s alternator. It drove a dummy resistive load, working superbly over very rough 75,000 km. It still lives today – charging a battery for our garden’s outside lighting.

The Tvan’s roof held a 50-watt solar module. This charged a 100 amp-hour AGM battery via another PL20. Its load was two 5-watt LEDs, an external 5-watt LED, water pump and a diesel-powered heater. It also drove a laptop computer via Telstra Next G. In ultra-cold areas it drove a 12-volt electric blanket for half an hour or so. The total load was less than 20 amp-hours/day. The two systems could be interconnected – but never needed.

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Plasmatronic PL20 regulator indicates a comforting 12.5 volts (in the TVan). Pic: rvbooks.com.au

Our solar equipped RVs – Nissan Patrol/TVan in use

The Nissan/TVan solar worked so well I strongly recommend the approach. It works particularly well for 4WDs towing camper trailers. A TVan has limited space and carrying capacity, but the we travelled, the less we realised one needs to carry. After a year or three, we always had ample space left over.

All three of our solar-equipped RVs worked without any problems over a combined 165,000 km. Of that, over 100,000 km was on Australia’s badly corrugated dirt tracks. Often in 36-40º C.

Collyn’s Books

Collyn Rivers’ books include the Caravan & Motorhome Book, the Camper Trailer Book, Caravan & Motorhome Electrics, Solar That Really Works (for boats, cabins and RVs) and Solar Success (for home and property systems).

Solar That Really Works!

Solar that Really Works! covers the design, installation and use of solar in cabins, camper trailers, caravans, fifth wheelers, campervans and motor homes.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Solar That Really Works!  Just ask.
ISBN: 978-0-6483190-3-0

Solar That Really Works!

Solar that Really Works! covers the design, installation and use of solar in cabins, camper trailers, caravans, fifth wheelers, campervans and motor homes.

eBook versions

Paperback version

The book retailers set their own prices which can vary substantially. We'll aim to keep a selection of the better prices above.

Any bookshop, whether online or bricks and mortar, can order copies of Solar That Really Works!  Just ask.
ISBN: 978-0-6483190-3-0