Perhaps the single biggest product to explode onto the marine electrical market in the last 10 years is the DC to AC power inverter. By simply converting 12 or 24V DC battery power to 230V AC mains electricity, boat owners are able to operate all kinds of appliances from computers to microwaves and hairdryers to toasters - without shore power or an on board generator.

The concept of the inverter is not new - the first units were around in World War II.

However, only technology available within the last 10-15 years has made them compact and efficient enough to be suitable for general marine use.

The style of inverter we are all familiar with today was pioneered by Vancouver based Statpower Technologies. From humble beginnings, their PROwatt range of inverters pushed the company into massive growth - and were recognised as one of Canada's top performing companies.

Acquired by Xantrex (which also took over well known inverter manufacturers Trace Engineering and Heart Interface), this group is now the world's largest inverter manufacturer, turning over in excess of US$105 million.

Inverter mass market Almost all lower cost inverters are based on the original PROwatt design of 10 years ago, but are manufactured by companies in China and Taiwan. Personal experiences of this market have proved that quality varies dramatically between the various suppliers - all who compete fiercely on price.

While sourcing a new range of inverter products, I looked at 15 separate manufacturers - from these only two product lines met the full CE requirements for safety and EMC (Electro Magnetic Compatibility).

Successful companies in this bracket have done two things well - quality control and marketing. Mass market inverters need to work properly, otherwise returned product starts to equal sales - and with the volumes involved could end up expensive - and they need to sell themselves off the shelf.

Two companies that have met this challenge particularly well are Waeco and Sinergex.

Waeco is best known for its range of refrigeration products sold through chandlery outlets and used by many boatbuilders.

To this they added an inverter range that could be sold through the same distribution channels. Their range covers 150 to 1800 watts and is competitively priced.

Formed by Adam Heindorff three years ago, Sinergex Technologies offers a wide range of units ideal for sale through chandlery and electronic outlets.

Heindorff worked alongside existing inverter distributors throughout the world and had his units designed and manufactured in the Far East.

This ensured he achieved the difficult balance between quality and cost.

After getting the product range right, Heindorff invested properly in marketing - to achieve a well branded and packaged product. Today Sinergex inverters are sold throughout the UK, Europe, USA and Australasia.

Sinergex is also looking to launch a new range of value priced battery chargers at METS.

High value inverters Three companies dominate the higher end of the inverter market - Mastervolt, Victron Energy and Xantrex.

All three companies have similar inverter offerings that utilise super efficient power conversion technology and clean, filtered AC outputs.

Unlike mass market inverters, the units available in this category all produce a pure sine wave output rather than modified sine wave.

230V AC power oscillates between +230V and -230V at fifty times per second. The transition between these two voltages is smooth - and when traced out on paper forms a sine wave.

This is difficult and expensive to achieve electronically with an inverter, so lower cost units replicate this by switching the voltage in the following sequence: 0V, +165V, +230V, +165V, 0V, -165V, -230V, -165V, 0V and so on.

This traced out forms a stepped wave form known as modified sine wave. While modified sine wave operates most 230V appliances satisfactorily, it doesn't work televisions, audio equipment, motors (in washing machines, etc) particularly well.

Pure sine wave inverters can be used with any piece of AC equipment without any compatibility issues.

Battery Chargers Used in vast quantities, battery chargers are another commodity product in the marine market. Again, the charger market is split much like that for inverters.

Unlike those used in the automotive market, marine chargers provide a multi stage charge - known as three or four stage charging (both are the same). Three stage charging has made a massive impact on marine electrical systems - giving properly (and fully) recharged batteries every time the boat plugs into shore power.

Considering that this type of charger is fitted to almost every boat, it is extremely surprising that most customers - and people working in the marine industry - don't understand the concept.

Standard automotive chargers have a fixed voltage and current output that reduces over time.

This is caused by internal resistance of the battery and only recharges them to around 60-70% of their capacity.

Three stage chargers have variable charging voltages that overcome battery internal resistance allowing the charger to fully recharge batteries to 100%.

Occupying the chandlery end of the battery charger market is Waeco and Sterling, which compete fiercely on price in the 10-50 Amp range of chargers.

Both ranges are sold in attractive self sale packaging for chandleries.

Higher end chargers Differences between mass market chargers and higher end units are somewhat more subtle than that of inverters.

The main differences include method of power conversion, control and additional features.

Occupied by Cristec, Mastervolt, Reya, Tecsup and Victron competition is extremely tough and each manufacturer strives to add better features for longer lasting batteries, faster recharge times and ease of use.

Both Victron and Tecsup have introduced a new charging regime that offers highly accurate charging.

Known as "adaptive" charging, these units cannot cause overcharging of expensive domestic battery banks.

Other three stage chargers use a timer to provide charge in the bulk (generally eight hours) and absorption (six hours) modes.

Victron and Tecsup argue that if the charger is plugged in and used when the batteries are slightly discharged, they will be subjected to at least 14 hours of recharging - and will be overcharged.

Adaptive chargers continuously test the batteries and adjust their charging regime according to the battery's state of charge. This prevents overcharging and extends the life of more exotic batteries such as gel and AGM types.

Victron is currently launching two new ranges of chargers - one low cost unit with basic specifications (non adaptive) for OEM fit. The other with full adaptive charge characteristics - there is also talk of end users being able to retrofit a small PCB to convert their basic spec unit up to being fully adaptive.

Victron has also incorporated this technology into their new multi inverter/charger.

Tecsup's HiTec range now features fully adaptive charging for accurate charging.

They've also incorporated a battery maintenance mode that looks after batteries over the winter.

Once in float mode, these units will provide a short charge at a higher voltage every 21 days - this combats sulphation and stratification within the battery bank.

The next two years should prove extremely interesting in the inverter and charger market. With new innovations, power conversion technologies, understanding of customer needs and lower cost, these power conversion products will become even more mainstream than they are now.

Perhaps the most interesting development in the on board generator market is the new WhiperGen from Victron Energy. Unlike other onboard generators (mainly designed solely to provide 230V AC power), the WhisperGen is a complete CHP (combined heat/power plant) for boats from 40ft plus.

External combustion The unit is unique since it employs the rarely seen Stirling external combustion engine. The WhisperGen is based on a four cylinder unit that works by repeatedly heating and cooling a mass of nitrogen gas. The rapid expansion and contraction of the gas drives the cylinders.

This in turn drives an alternator creating DC power.

The abundant excess heat from the combustion process is then used to drive a calorifier and onboard (either conventional radiator or blown air) central heating. With a maximum heat output of 8kW, the unit is able to provide more than enough power on average vessels.

So what? Surely this is available with a standard diesel set. True, but the WhisperGen is designed to run more or less continuously using just 0.8 litres (0.2 gallons) of diesel per hour. The microprocessor-controlled charging system develops a proper 3-stage charge providing over 1600AH (@12V) of battery charging per day.

With over 1600AH per day of battery power available, the WhisperGen is ideal for those planning all electric galleys (by using a large enough inverter).

This unit's overall size is comparatively smaller than an equivalent generator required to do the same job (measuring 650x450x500mm) and runs silent producing just 44 dBA - so neighbours rafted up alongside won't complain.

Caterpillar has extended its small marine generator range with the launch of the C1.5 at the Southampton Boat Show.

This is the fourth model in a new range of generator sets that will span power outputs from 9 ekW to 99 ekW when the fifth model, the 9 ekW 1.5 litre, C1.1, is introduced at the end of 2004.

The new Caterpillar C1.5 genset utilises an indirect injection, naturally aspirated 1.5-litre, 3-cylinder, 4-stroke Cat engine with a cast aluminium expansion tank and exhaust manifold, a sea water pump with ceramic seals to ensure a long life, and a triple-pass heat exchanger with optional keel cooling for open sets.

The C1.5 also has electronic governing that provides isochronous control of the engine speed and offers easy changing between 50 Hz and 60 Hz.

Designed for single-sided servicing and single point lifting, Caterpillar says the C1.5 has extended service intervals of 500 hours, operates with no visible emissions and offers straightforward "plug and play" performance and stable frequency. The C1.5 is available with both 12V and 24V starter/alternator options.

Automatic safety shutdowns include over-speed, high fresh water temperature, low engine oil pressure and, when fitted with a wet exhaust system, high exhaust temperature.

For the last 15 years Fischer Panda has been producing asynchronous AC generators that are failsafe and compact, in sizes from 3.8kW up to 111kW, in 34 standard models with single phase, 3-phase or both.

Not needing any airflow to cool the alternator, the company claims to be truly 100% watercooled, resulting in what they say are the most compact and quietest designs being achieved.

Rod Boreham says the temperature stability from true watercooling ensures the generator will supply its rated output even when the ambient air temperature is very high.

The company actively promotes the virtues of 3000rpm generators (fast-runners), which they say in many cases is the better speed for a 50Hz diesel engine generator.

However, the company also makes a range of 1500rpm units (slow runners), from 6.5kW up to 111 kW.

The new E-TEC system on AC generators integrates the generator more closely to the AC system on the yacht. AC generators are sized for the peak demand they will normally have to cope with, until available space caps the physical size of the generator.

If the generator could intelligently turn off low priority consumers (eg; battery chargers and water heaters) when short term immediate demand would cause the total demand to exceed the generator rating (ie; a cooker or hair drier), and then turn them back on again afterwards - there would be no problem.

Fischer Panda says with ETEC, a smaller generator than previously specified could now be selected.

Often, the primary need for a generator is to charge batteries, sometimes coupled to inverters to supply offline AC, and Fischer Panda claims to lead the way in the development of diesel powered DC generators with power outputs from 4kW up to 20kW, in five standard models available in any voltage required (not just 12V and 24V, but also 48V, 72V, 96V etc).

The company's 4kW DC generator can supply a peak of 280A at 12V. To put this into perspective, they say this would recharge a depleted 400Ah service battery bank in less than one hour.

The DC system is supplied with an auto start/stop feature using battery voltage sensing as the trigger.

David Melville says GenACis' Dolphin M3D, previewed at Earls Court in January this year and centre stage at the Southampton Boat Show last month, is the result of 15 years of generator evolution, fully boat tested at every stage.

The unit weighs just 56kgs and is less than 450 x 320mm.

The output is a steady 3kVA (2.7kW) at 230v and, as an option, there is an economy speed device switching the output to 1.7kW for longer periods (battery charging absorption, etc) with minimal fuel consumption plus savings on wear and tear.

Scott Pettifer says HFL hashad a good year - "it's been steady, even though market conditions have changed dramatically over the year".

Generator-wise it's been pretty good and on air conditioning, we're noticing a rapid increase in enquiries over the past five or six months. It's OEM and export market, plus some retro-fit in the Middle East.

HFL has been doing well with its Isuzu-based Ranger gensets up to 35KVA. "We also use Cummins and Perkins, " sad Pettifer, "but we've done quite a bit of work with the Isuzu."

The Isuzu is an understated brand in this country, he said.

It's one of the largest diesel engine makers in the world and they produce workhorses and just keep going and going.

"We 're doing a lot of product development work and I think the next 12 months will be very exciting, " he told BB .With 2,000 Watts of power the Handy Honda EU20i is, says Honda , a versatile tool for a multitude of portable power applications.

While big on performance, Honda says the generator is no heavyweight. At 21kg, they claim, the EU20i has the best power-to-weight ratio of any generator in its class and is the envy of noisy smelly 2-stroke neighbours.

Kohler Power Systems launched a complete new range of marine diesel generators from 6.5 - 32kW at the recent Genoa Boat Show.

The new range features advanced digital control (ADC), improved sound shields and, says UK distributor AMP, even simpler installation.

AMP says the Kohler range of marine generators is geared towards power and sail leisure craft, but is being increasingly welcomed by commercial users.

The new ADC controller offers precise regulation of voltage and hertz to cope with the demands of modern day electronics and lighting, push button set up, digital diagnostics, auto start and supports CAN BUS (J1939) output.

Mastervolt UK has been appointed suppliers of 12V and 24V battery chargers to Princess Yachts International.

The Princess powerboats and Moody sailboats on display at the recent Southampton Boat Show all featured the new chargers in Mastervolt approved installations.

Mastervolt says chosen to accommodate the demand for ever increasing DC electrical loads, its intelligent three stage bulk/float/absorption charging characteristics will give an estimated 20% improved charging capability.

Neil Phelps says Berthon's Onan business is doing well and says Onan has been concentrating on petrol sets for sale in the USA.

But Phelps reckons the genset business in the UK will hot up as Kohler and Cat bring new products online. In the meantime, he says, remember that Onan's e-QD is still the only microprocessor-controlled range of gensets.

Perkins Sabre has added a new model to its genset engine range to extend the lower end of the output options.

The new 422GM is a compact, 4-cylinder, 2.2-litre indirect injection, naturally aspirated engine that delivers a maximum net engine power output of 20.2RWm at 1,500rpm, and 24.2kWm at 1,800rpm, while the continuous net engine power output at 1,500rpm is 18.4kWm and at 1,800rpm is 22.0.

Contacts: Caterpillar Finning (UK) T: 01453 461461 F: 01453 461797 W: finning.co.uk<$>Fischer Panda UK.T: 01202 820840. F: 01202 828688 E: info@fischerpanda.co.uk W: fischerpanda.co.uk GenACis T: 0202 624356 F: 01202 625842 E: david@genacis.com HFL T: 020 8805 9088 F: 020 8805 2440 E: sales@hflgen.com W: hflgen.com Honda T: 01753 590545 W: hondaenergy.co.uk<$>Kohler Power Systems Atlantis Marine Power Ltd T: 01752 208810. F: 01752 208811 E: sales@atlantismarine.co.uk W: atlantismarine.co.uk Mastervolt UK T: 01794 516443. F: 01794 516453 E: info@mastervolt.co.uk W: mastervolt.co.uk Onan Berthon Boat Company T: 01590 673312. F: 01590 647445 E: onan@berthon.co.uk W: berthongroup.co.uk Perkins Sabre T: 01202 893720 F: 01202 851700 E: post@sabre-engines.co.uk W: perkins-sabre.com

Contacts:

Cristec www.cristec.fr<$>Mastervolt www.mastervolt.com<$>Reya www.reya.com<$>Sinergex www.sinergex.com<$>Sterling www.sterling-power.com<$>Tecsup www.tecsup.fr Victron<$>Energy www.victronenergy.com<$>Waeco www.waeco.co.uk