Honda EU10i Genset

As Honda has recently released an upgraded version of the EU10i portable generator known as the EU20i, which produces a maximum output of 2.0kVa but weighs only 20kg, it's worthwhile considering how successful this concept has been.

Triggs of Toronto, NSW, a Honda Power Equipment dealer for the past decade, told me recently that the EU10i sold like hotcakes when first introduced in late 1999. Apparently, buyers were paranoid about the looming Y2K scare and bought them for emergency power should the public utilities fail.

But the EU10i has also proven extremely popular with owners of small timber yachts left on moorings. The genset is light enough to be transported out in a dinghy but powerful enough to run sanders and other tools. When the job is finished, the owners carry them ashore again to eliminate the possibility of theft.

The EU10i was the world's first truly portable generator capable of powering PCs and other frequency-sensitive equipment. It has a maximum output of 1.0kVa and a maximum continuous (rated) output of 0.9kVa at a power rating of 1.0.

Unlike conventional gensets, where the engine drives an alternator at a steady 3000rpm to produce 240V and 50Hz (cycles per second) of frequency, the EU10i uses a sinewave inverter, which allows the engine to run at varying speeds according to the load connected. The electricity produced is of commercial quality and, from my experience, is better than some domestic supply companies can provide!

By incorporating the alternator windings in the flywheel, the EU10i weighs only 13kg (without fuel or oil) and measures a compact 450mm long, 240mm wide and 380mm high.

Two throttle settings or modes are provided. One mode provides the normal rated engine speed, while the other is known as the 'Eco Throttle' and varies the engine speed via a 'stepper motor' control.

Fixed-rev gensets need at least 50% of rated load to prevent engine damage through insufficient load. But the EU10i can be run all day on very little load without damaging the engine. There's a slight hesitation as the motor steps to its next level as load increases, but the inverter ensures there's no fluctuation in electricity supply, unlike the old fixed-speed gensets.

Another feature is the Parallel Operation Cable, which allows two gensets to be run simultaneously to provide a total of 1.8kVa continuous or 2.0kVa maximum. All operation is done from one unit, just like the way diesel-electric locomotives are coupled with the leading loco controlling the others!

Because the EU10i revs out to 5500rpm, it needs only a 1.8hp, 50cc OHV unit. The powerhead has an 0.25lt sump, pressure lubrication and can operate at temperatures of up to 40°C. It also has a sensor for low oil level, which either shuts down the engine or prevents it from being started. The fuel tank holds 2.3lt and has a removable filler-neck screen for easy cleaning.

Fuel consumption is way below fixed-rev gensets. For example, at 75W the consumption is a mere 0.20lt/h. At 225W or one quarter of the rated load, the consumption averages 0.30lt/h and fuel/oil ratio 1190:1. At half load or 450W, the consumption averages 0.33lt/h and F/O ratio 520:1.

At 675W the engine revs much faster and uses 0.43lt/h with an F/O ratio of 320:1, but the revs don't increase much to 900W or maximum continuous load, where the EU10i uses 0.52lt/h.

Despite its small engine, the EU10i easily starts a 400W 10mm drill/orbital sander unit while powering a 150W Portaflood, and starts a 150W camping fridge while running four Portafloods. No other genset I've tested under 1.0kVa can do this.

The Eco Throttle also allows the engine to be warmed up at idle speeds before load is applied, and this will definitely increase engine lifespan.

Unfortunately, to charge 12V batteries simultaneously while providing 240V power, the EU10i must be run with the Eco Throttle off. The DC current is not regulated and produces a constant 8amp, so it should only be used with normal marine starting batteries of at least 70amp/hr. But at least it can be used in conjunction with the AC circuit, so you can charge your boat's batteries while watching TV or running a PC.

When the Eco Throttle is switched off, the engine consumes 0.38lt/h at 450W, 0.47lt/h at 675W and 0.58lt/h at 900W, and as a steady 5500rpm is maintained on this setting, at least 450W of load should be maintained to increase engine lifespan.

Over the two and a half years I have been testing the loan unit, it has normally started first pull, hot or cold. The only time it blew a puff of oil smoke was after it was left unused for three months.

A total of 240 running hours have been clocked-up using semi-synthetic SAE 10W50 Valvoline Syngard from the initial 10hr service onwards. Averaging 360W with a total of 2.25% 1.0kVa and 4.5% Eco Throttle 'off' operation, the fuel consumption averaged 0.31lt/h and the F/O ratio 574:1.

Like all Hondas I've tested, the EU10i requires around 200 running hours to fully run in. For example, from 160-240hr, averaging 360W, the fuel consumption was 0.30lt/h and the F/O ratio had improved to 968:1.

The only operating problem over the entire evaluation period has been the occasional loss of power due to a loose spark plug. But the original spark plug lasted 240 running hours and was replaced only because the carbon deposits were getting too hard to remove.

However, the foam aircleaner element should be cleaned every 50 running hours and most of the oil squeezed out, or the engine will run rich due to starvation of air. And halve the 100hr oil change interval, as the oil in the loan unit has always been dirty after each 50hr period.

Really, the only dealer service required is at 300hr, when the valve clearance should be checked.

According to Triggs (tel: (02) 4950 5225), the labour costs for this service are only $50.

As of May, the EU10i retailed for $1639 and the EU20i for $2269.