Updated June 2017
Our three solar equipped RVs covered over 175,000 km mainly in Australia’s vast outback. They used none but solar and alternator power – 100% reliably.
Our solar equipped RVs – VW Kombi
The first of our solar equipped RVs was a now rare 1971 VW Kombi Westfalia camper. We modified it during 1994 for extensive Australia dirt road usage. It had an 80 watt Solarex solar panel on a roof-mounted tiltable base and a basic solar regulator. The 100 amp hour deep cycle battery was also alternator charged whilst driving. A voltage sensing relay specifically protected the starter battery from overly discharging.
The trustworthy VW Kombi and my wife (Maarit) just off the Strzelecki track – camping overnight. Pic: caravanandmotorhomebooks.com
The system powered a 40 watt Engel chest fridge. It also powered three 20 watt halogen globes (of which only two were used simultaneously). Solar capacity was less than I advise nowadays however. But this was in an era where even 80 watts cost about $750 (at least $1500 in today’s terms). It worked particularly well because we travelled mostly in northern Australia, where sunlight is adequate and reliable.
The Kombi proved 100% reliable over some 35,000 km of mostly corrugated dirt tracks. These included the Birdsville, Oodnadatta and Strzelecki. Its low slung rear engine, however, precluded deep water crossings. Primarily because of this, it was thus sold a few years later.
Our solar equipped RVs – the OKA
Our next of our solar equipped RVs was an OKA. This is an Australian-designed and built 5.5 tonne 4WD truck intended for mining and quarry type use. Some 550 or so were built from 1993-2010 or so, but then ceased production. They are now particularly sought after. OKAs, above all, make stunningly reliable go-anywhere motor homes. Most sell for well over their original new price even after several hundred thousand kilometres!. Ours was a 1994 coach-bodied version. It was purchased after a particularly hard nine months in a Singleton coal mine.
Our OKA crossing the Wenlock river on the track to the top of Australia’s Cape York. The white dome is the antenna for our Westinghouse satellite phone. Pic: caravanandmotorhomebooks.com
The roof was replaced by a custom-made fibreglass pop-top. A dinette/double bed plus kitchen and extensive storage was built of white powder-coated aluminium. 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 (originally) 400 amp hour lead acid deep cycle battery bank. It did so via an early TWC smart alternator regulator. An early Redarc voltage sensing relay protected the starter battery. Two 100 watt Solarex solar panels were located over the driving cab. These charged via a Plasmatronic PL20 regulator.
The main loads
The main loads were a 71 litre eutectic Oz Fridge, plus a huge Westinghouse satellite telephone/fax system. The latter was the size of a large suitcase. It weighed about 15 kg. Its dome antenna can be seen in the photograph above.
Lighting back then was still halogen globes. We had 12 (each switchable) of 10 and 20 watts.
This vehicle was used extensively for driving across Australia (via Alice Springs) from our then home in Broome (see All Solar House) to the east coast and back. This return trip of some 13,000 km was done 12 times in the OKA. And subsequently three times with its successor. Some 80% of each return trip was off-road. It usually required 6-8 days each way.
The satellite fax/telephone likewise proved totally reliable, but it gobbled energy. It was thus replaced in 2002 by an early hand-held version. This substantially reduced the OKA’s energy draw. That, in turn, enabled us to reduce (house) battery capacity. We thus used a single 120 amp hour sealed lead acid deep cycle unit.
An OKA is particularly ideal for traversing long distances over rough going. It is, however, too large and unwieldy for everyday use.
In 2006 we reluctantly sold it to a buyer from Queensland. (He flew over and drove it back – some 7000 km). It was subsequently restored to ‘better than new’ condition.
Our solar equipped RVs – Nissan Patrol/TVan
The third of our solar equipped RVs was one of the very first 780 kg Track Trailer Tvans. It was pulled with ease by our 2005, 4.2 litre TD Nissan Patrol. For this, we decided to go virtually all-solar. Each part had its own self-contained system. (Alternator charging, however, was only needed in the Nissan. It was during a week-long overcast down south).
The Nissan had two by 100 watts Solarex solar panels. These were on bars on the Nissan’s roof. They charged a 110 amp hour Ritar AGM battery via a Plasmatronic PL 40 regulator. The alternator was not normally used for charging. If needed it was done via a manually switched voltage sensing relay. The Nissan’s main load was a 60 litre slide-out Engel fridge.
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. This was on long term (three years) off-road trial. It was driven from the Nissan’s alternator. For assured constancy, it drove a dummy resistive (external) load. The unit worked superbly over some very rough 100,000 km. It still works (7 years later) in semi-retirement. It currently charges a battery for garden lighting.
Plasmatronic PL20 indicates a comforting 12.5 volts on load (in the TVan) Pic: caravanandmotorhomebooks.com
Our solar equipped RVs – the Tvan
The TVan had a single roof-mounted 50 watt Sharp solar module. This charged a 100 amp hour AGM battery via a Plasmatronic PL20. The lighting load was via two by 5 watt interior LEDs and external 5 watt LED. Also powered was a water pump, a diesel-interior heater and laptop computer. If very cold, it ran a 12 volt electric blanket or an hour or so.
This only seems a heavy load. It was typically less than 15 amp hours a day. Solar alone covered adequately, even in winter months up north and summer down south. I would have preferred more solar capacity, but there was no available space.
The two systems could be interconnected if needed (but never were).
Our solar equipped RVs – a recommended system
The Nissan/Tvan dual system worked extremely well. I strongly recommend this dual system approach for solar equipped RVs. It works particularly for 4WDs towing camper trailers. It requires roof space for the solar modules. The more one travels, however, the less one tends to carry. We thus had no need to carry anything other than solar modules on the roof rack.
Each system worked without any problems over a combined plus 175,000 km. About 125,000 km was on Australia’s inland corrugated dirt roads. Frequently in 360– 400 C heat.
Our solar equipped RVs – further information
Those into serious off-road travel may be particularly interested in the author’s 1959-1960 trans-Africa trip – Driving Across Africa. It is also available as a stunning DVD directly from Caravan & Motorhome Books, PO Box 365. Church Point, NSW 2105. Australia. It costs A$15 – or six for $A50 (sale limited to Australia only at present.)
Full details of designing, installing and using solar are in my books Solar That Really Works! and Caravan & Motorhome Electrics. See also constantly updated articles on RV solar and electrics. They are on our associated: caravanandmotorhomebooks.com.