CAMPING - POWER & LIGHTING
Solar power can be a viable camping power source, but the portable generator/battery charger still has its place, particularly in situations where sunlight is unreliable.
If you’re planning to camp in remote areas of the Victorian High Country, or along the Great Dividing Range from the NSW-Victorian Border to North Queensland you can’t rely on solar power alone, because the sun’s rays may not make it through cloud, mist or the thick leaf canopy. A portable generator may be handy to recharge your fridge battery.
However, take note of the fact that nearly all camping parks, most National Parks and many other sites completely ban the use of generators at any time. Bush camping is different, because it’s often possible to set up well away from other campers and that’s when the little genny comes into its own.
A generator’s role is to act as a backup power source, supporting the vehicle’s starting battery, deep-cycle fridge battery(s), solar panel with at least 100-watt capacity and to run one or two 240V appliances.
Generator battery charging
During Outback Travel Australia’s many remote-area forays we’ve needed to use our backup Honda portable generator on many occasions – most often when the sun wouldn’t shine.
The solution has been to hook up the petrol generator’s 12-volt leads to the deep-cycle battery for a couple of hours, before the battery load voltage has dropped below 12V: to ensure the fridge stayed safely cold and boosted the battery voltage at the same time.
Note that this is not the optimum way to charge a dead-flat battery, because the voltage is a nominal 12V and the current is only around eight amps, but it will work.
If you intend to use your petrol generator to charge 12V starting or deep-cycle batteries on a regular basis that’s best done using the generator’s 240V circuit, via the same modern, electronically controlled battery charger you use at home with mains voltage, but even then it can take several hours to recharge a flat battery.
A faster alternative is a purpose-built, petrol-powered battery charger that combines a vehicle alternator with a petrol engine, delivering 14+V and around seven times the battery charging current of a portable generator.
We’ve used a Christie charger on several bush trips and found it very useful.
Which Portable Generator for You
A portable generator that meets bush-travel criteria isn’t going to be one of the hardware chain ‘cheapies’, because they don’t deliver electricity flow of sufficient quality to meet the needs of delicate electronic equipment. The minimum requirement you should look for is a four-stroke – not two-stroke – inverter/generator that produces pure sine wave power and we’ve not seen anything in the market below around $600 that fulfils these criteria.
Most low-priced generators rotate two coils of wire inside a circumference of magnets and the engine must maintain a constant speed of 50 cycles per second or 3000 cycles per minute (3000rpm) to produce the standard 50 Hz (cycles per second) of mains-equivalent power frequency. If electrical
load makes the engine revs change the frequency is disturbed.
The engine in an inverter/generator rotates several small coils of wire in a circumference of very strong magnets. Each rotation of the engine produces some 300 overlapping sine waves of AC power. Engine speed can then reflect electrical load, without disturbing frequency, so an inverter/generator with less than full load can run at lower speed, potentially saving fuel and reducing noise.
Speaking of noise, most quality generators are built to comply with the USA’s National Park Service (NPS) noise limit. This limit is expressed in decibels and shown as dB(A): the most common global measurement of sound pressure level. The US NPS generator noise limit is 60dB(A) at 50 feet (15.2m) from the source, 67dB(A) at 23 feet (7m) and 74dB(A) at 10 feet (3m).
Quality generators have a ‘low noise’ operating switch that drops output, but makes the generator much more neighbour-friendly.
So, which inverter/generator should you buy? The decision should be made on the basis of power requirements, after-sales support and price.
If you need only backup power, with the ability to keep the fridge going when your solar power isn’t working and run a couple of LED lights, a small generator will do the trick. Around 700 watts continuous power is as small as they get.
To run a camping fridge, TV or computer and lights, all at the same time, requires bout 700 watts of continuous power. Add a small freezer and a microwave and the demand doubles to around 1400W and if you wanted to replicate the comforts of home, including an aircon unit and coffee machine, you’d need around 3000W.
Some people prefer to buy a generator that can also be used as power backup at home, to keep essential items operating. The rule in this case is to buy the most powerful one that you can fit into your camping vehicle.
For the widest choice of portable generators on-line, check out My Generator.
Christie Battery Charger
This petrol-powered battery charger consists of a Honda GXH50, 50cc,1.6kW four-stroke engine driving a Bosch 12V/55A automotive alternator. It can be set manually for low (14V) or high (14.6V) charge rates and delivers up to 55 amps. High-current, three-metre leads, with heavy-duty alligator clamps are
It’s very noisy in operation, but usually needs to run for only a few minutes to put enough charge into a starting battery. Not ideal for running a fridge
for extended periods.
Tank capacity is 1.2L and consumption is around 0.75L/hr.
The Christie 12/55 measures 410mm long, 275mm wide and 370 mm high, and weighs 12kg.
The LPG option
Propane-fuelled generators are very popular in the USA, but are virtually unknown here. We can’t understand this situation, because most caravans and camper trailers carry LPG bottles that could easily be used to run generators as well as for cooking and heating water.
As far as we can discover the only off-the-shelf LPG generators in Australia are Elgas’ Green Power models.
However, there are conversion kits available on-line for petrol generators and some of them retain the existing carburettor, allowing the engine to run on natural gas, LPG or petrol.
EFOY Fuel Cell
There’s little doubt that this is a glimpse into the future. The German-made EFOY fuel cell battery charger is rated at 65-watt output and has automatic control over a capacity of 1600 Watt-hours (130 amp-hours) per day at 5.4A.
The fuel cell requires minimal ventilation and can operate in an almost closed environment, while the vehicle is moving. Emissions are water vapour and CO2 – no carbon monoxide.
The EFOY stack runs on methanol that comes in a 10-litre plastic container, costing $60. Consumption rate is 70ml/AH.
The 1600W cell measures 435mm long, 200mm wide and 276mm high, and weighs only 7.6kg. Claimed noise level is 23dB(A) at 7m.
RRP for the EFOY 1600W fuel cell is $6600. EFOY 2200W is $8400
How fuel cells work
A fuel cell is a much quieter, lighter, more efficient and less polluting user of hydrocarbon fuels than a combustion generator. Fuel cells are able to operate in a semi-enclosed environment and emit no carbon monoxide (CO). However, the technology is in its infancy and is very expensive. The big customers for fuel cells are military users, who need, quiet, lightweight, reliable generating power and damn the expense.
A fuel cell converts chemical energy into electrical energy, in a transformation that is efficient and involves no moving parts and almost no noise.
The chemical action that provides electric current takes place between hydrogen and oxygen atoms, so with straight hydrogen as a fuel there would be no emissions other than water vapour (H2O).
However, existing, commercially available fuel cells use hydrocarbon liquid fuels, so carbon dioxide (CO2) is emitted as well.
In theory, ethanol (CH3CH2OH) is the ideal liquid fuel, because it’s cheap and readily available, but its relatively complex atomic
structure has so far refused to oxidise readily in test fuel cells.
Methanol (CH3OH) – also known as methyl alcohol, wood alcohol, wood naphtha or wood spirits – has a simpler structure that works well.
The centre of every fuel cell is a ‘stack’, which consists of an anode, a cathode and a membrane that acts as an electrolyte, separating the anode and the cathode from each other.
Methanol and water are introduced on the anode side while ambient air, containing oxygen, enters the cathode side. H+ ions, free electrons and carbon dioxide arise on the anode side and, while the positively charged electrical particles (protons) can permeate the membrane, the negatively charged electrons are forced to travel through a circuit over to the cathode side, thereby producing electrical current.
Oxidised carbon atoms are emitted as CO2 on the anode side and oxidised hydrogen (water vapour) emerges from the cathode side.
Generator Safety – Be Aware
If you’re standing near an old-fashioned generator it commands respect, because this dirty, smelly machine is extremely noisy, so you know something dangerous is going on. In contrast, a plastic-shrouded, modern portable generator makes only a gentle humming noise, so it seems quite innocuous.
However, all petrol-powered generators produce deadly carbon monoxide gas, which is invisible and odourless. Don’t even think about operating one in an enclosed space.
Also, the 240-volt power outlet on a portable generator can kill, just as easily as a household power point.
Never leave a running generator unattended: more than one devastating bushfire has started this way.
Never refuel a hot generator, whether it’s running or not. Hot engine parts can ignite petrol. Always turn the generator off and allow it to cool down before refuelling.
Turn off all connected appliances before starting your generator and turn them on one at a time; never exceeding the generator’s rated wattage.
Some older generators have 12V battery charging leads that can be unintentionally pushed into the 240V outlet holes. Get rid of them immediately and replace them with dedicated 12V leads, because 240-volt current running through 12-volt battery leads has caused at least one fatality.