We personally drove our solar equipped RVs some 130,000 km over most of Australia’s inland dirt tracks. Nothing failed in that distance (and 20 years).
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. It had a single Solarex 80 watt solar panel that we mounted on a tiltable base, a very basic solar regulator and a 100 amp hour battery. The battery was also charged, via a voltage sensing relay, from the VW’s alternator.
The trustworthy VW Kombi and my wife (Maarit) just off the Strzelecki track – camping overnight. Pic: caravanandmotorhomebooks.com
This powered a 40 watt Engel chest fridge plus internal and external lighting via three 20 watt halogen globes (of which only two were ever used simultaneously). Solar was very costly back then so whilst less than I now advise, it worked well for us as our travelling was mostly in areas of ample and reliable sun.
The Kombi proved 100% reliable over some 25,000 km of mostly corrugated dirt tracks (including the Birdsville, Oodnadatta and Strzelecki). Its low slung engine however precluded deep water crossings. Further, a Kombi is extremely hard to keep in a straight line on mud. It was sold a few years later when we purchased an OKA ex-mining truck.
Our solar equipped RVs – the OKA
An OKA is a totally Australian designed and built 5.5 tonne 4WD truck intended for fully off-road use. Some 550 or so were built from 1993-2010 or so. They then ceased production. They are now very much sought after as they make stunning go-anywhere motor homes. Most sell for well over their original new price even after several hundred thousand kilometres! Ours was the 14 seater coach-bodied version and made in 1994.
The OKA crossing the Wenlock river on the track up to the tip of Australia’s Cape York – the dome in front of the solar panels is the active antenna for the Westinghouse satellite phone. Pic: caravanandmotorhomebooks.com
The roof was replaced by a fibre glass pop-top. The interior was stripped and a dinette/double bed plus kitchen and storage was built using aluminium powder-coated white. The entire interior weighed less than 75 kg.
Twin 220 litre water tanks and twin 210 litre fuel tanks were installed, plus a second spare wheel and a firewood rack.
The alternator was replaced by a Bosch 140 amp unit. This charged the 400 amp hour lead acid deep cycle battery bank via an early TWC smart alternator regulator, via a voltage sensing relay. Two 100 watt Solarex solar panels were located on the rigid front part of the roof. They charged via a Plasmatronic PL20 regulator.
The main loads were a 71 litre eutectic Oz Fridge, plus a Westinghouse satellite telephone/fax system. These were the size of a large suitcase and weighed over 15 kg. Its dome antenna can be seen in the photograph.
Lighting was from up to 12 (each switchable) halogen globes of 10 and 20 watts each.
This vehicle was used extensively for driving across Australia (via Alice Springs) from our then home in Broome (see All Solar House on this site) to the east coast and back. The return trip (about 13,000 km) was done 12 times in the OKA and three times with its successor. Some 80% of each was off-road.
The Westinghouse satellite fax/telephone was 100% reliable – but energy hungry. It was replaced in 2002 when hand-held versions became available. This reduced the OKA’s energy draw, in turn enabling us to reduce (house) battery capacity to a single 120 amp hour sealed lead acid deep cycle battery.
Whilst ideal for its intended purpose- of traversing long distances over rough going – it is too large and unwieldy for everyday use. As we also had a 2005 Nissan 4.2 litre Nissan Patrol, a Suzuki Sierra, and a 2005 4WD dual cab Hilux, we reluctantly sold the OKA to a man who flew over from Queensland and drove it home. He restored it superbly.
The third of our solar equipped RVs was one of the first Track Trailer 780 kg TVans. It was pulled with relative ease by the Nissan Patrol.
Our solar equipped RVs – Nissan Patrol/TVan
For the Patrol/TVan rig we decided to go virtually all-solar.
Each part had its own self-contained system. The Nissan had two by 100 watts Solarex solar panels on roof bars that charged a 110 amp hour Ritar AGM battery (via a Plasmatronic PL 40 regulator). The alternator was not normally used for charging that battery. If needed it was done via a voltage sensing relay. Its main load was a 60 litre slide-out Engel fridge. It also drove a single outside light when camping.
Nissan Patrol and TVan set up for the night at Mitchells Falls (in Australia’s far-north Kimberley). Pic: caravanandmotorhomebooks.com
The Nissan also had the very first production model of the Redarc BMS 1215 Battery Management System on long term (some three years) off-road trial. This was driven from the Nissan’s alternator and drove a dummy resistive load. It worked superbly over very rough 75,000 km. It lives today in semi-retirement in our garage charging a battery for outside lighting.
The Tvan had a single roof mounted 50 watt Sharp solar module. This charged a 100 amp hour AGM battery via a Plasmatronic PL20. Its load was two 5 watt interior LEDs, an external 5 watt LED, a water pump, the pump and fan for a Webasto diesel-powered heater, my wife’s laptop computer, Telstra Next G email. If very it drove a 12 volt electric blanket for an hour or so. The load was typically less than 20 amp hours a day.
Plasmatronic PL20 indicates a comforting 12.5 volts on load (in the TVan). Pic: caravanandmotorhomebooks.com
The two systems could be interconnected – but that was never needed.
The Nissan/Tvan solar worked so well I strongly recommend this dual approach. It works particularly well for 4WDs towing camper trailers. It requires roof space for the solar – but the more one travels, the less one tends 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 130,000 km of which some 80,000 km or so was on Australia’s inland corrugated dirt roads – and often in 36-40 degrees C heat.
(Those interested in serious off-road travel may be interested in the author’s 1959-1960 trans-Africa trip – Last Drive Across Africa.)
Collyn Rivers’ books include the all-new 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). All can be bought directly from us. For information about the author see Bio.