Sceptics will always insist that the only truly quiet generator is one that’s switched off. And even ‘silent generator’ is very much a relative term, referring to units that slip under a certain sound output level.

While the majority of sites offer mains hook-up, most of us have at least one favourite place that’s little more than a well-kept field on a cliff-top, or behind a farm or pub.

You’re unlikely to find hook-up in such locations – and you certainly won’t if you’re wild camping – which means that you’ll need either a substantial solar set-up, or a generator, to enjoy your home comforts.

The same is true for ralliers, who need the ability to motorcaravan off-grid. Of course, not all parks allow generators, but many of the less commercial ones certainly do.

Before buying a generator, it’s worth scanning through the rules of your favourite sites before parting with cash.

Great-value generators

If you choose to take the plunge, now is a great time to buy. That’s because inverter generators – which are smaller, more e†fficient, quieter, and have a much more stable output – have suddenly dropped below the £200 mark.

In short, performance that was only, until recently, produced by premium branded models – nearing the £1000 mark – is now available for much less. Which is why we’ve decided to see just what you can get for £350 or less.

We started by comparing each unit’s output against its size and weight. As always, we prefer compact and lightweight models that perform.

Output-wise, we looked at four factors: maximum output, peak output, 12V output, and smoothness.

Maximum output, as you would expect, is the maximum wattage that the generator can output continually. Peak output is what the generator can stretch to for short periods, which is important because many modern electrical devices – such as fluorescent lights or anything with a motor – require a brief power surge to get them started.

Many people, at this point, assume that generators’ 12ŠˆV outputs rise in line with their AC outputs. Don’t fall into that trap!

Some small units have high 12V outputs, yet some larger models are really rather meagre in this respect. This is all the more critical for those motorcaravanners who plan to use the unit to charge high-capacity leisure batteries.

Because the level of power you need depends on what you take away with you, our scoring simply ensures that each unit’s output is in line with its price, size and weight.

Power delivery?

As well as ultimate power, we also checked the smoothness of output. Whereas mains sockets give out a steady 230ˆ‹‰V, conventional generator outputs can vary widely – often to the point that sensitive electronic devices (such as laptops, TVs or tablets) should not be powered by them directly.

Inverter generators use sophisticated electronics to tame the output and make it safe to use with most items. However, even inverters vary.

Some output true sine wave AC, others offer modified sine wave AC. The former is better and really is as safe as a mains socket.

Modified sine wave is a cheaper technology that can upset some sensitive devices, and often leads to a noticeable hiss from audio equipment.

The noise factor

Talking of noise, the quieter a generator is, the better. But we also consider the type of noise produced.

Clanking and tinny sounds are much more of a nuisance than a dull rumbling, but this isn’t reflected in the decibel scale used to rate noise levels.

Next, we factored-in efficiency by running a 450šŒ‰W panel heater off a set quantity of fuel, timing how long it took each model to devour the petrol given.

From this we calculated efficiency and how long each unit would power that heater with a tank full of petrol. Obviously, we prefer tank sizes that allow decent running times.

Finally, we prefer 4-stroke units to 2-strokes. Although modern 2-stroke engines are good they are always less effi†cient, and having to mix oil in with the fuel can be a messy affair.

One other point: as handles can often be cut through or unscrewed, some small generators are easy to steal, so consider how to safeguard your investment from thieves.

SIP Medusa T951 – two stars

While we stand by our score, we should point out that this isn’t a bad machine.

It’s just less impressive, in terms of performance and price, than the competition: specifically, Osaki’s OSA-273-3000‘‡’‡€€€K, which is very similar, but around £40 cheaper.

Both machines use surprisingly smooth-running 2-stroke engines, and kick out a 650W maximum with allowable peaks of 780W. On the 12V side, output is a very respectable 5.3‡A.

In mains mode, we were impressed by the output. It’s smoother than we expected, even if it’s no match for the super-smooth managed AC from inverter models.

Impax IM800i – four stars

Weighing in at 9.5kg and measuring 36 x 27 x 19ƒˆcm, it’s hard to imagine a more suitable generator for touring. It also proved to be one of the most frugal here.

And while the sound-level output of 93‡dBA isn’t great on paper, the noise produced is far less jarring and far more muted than many in the group.

Max output is a smooth pure sine 700W, with allowable peaks of 780W, which is perhaps lower than ideal to cover everything on tour.

The max 12V output of •4A is disappointing, too – large depleted leisure batteries require rather more to charge quickly.

Sealey G1000I – three stars

It’s a bizarre concept – mixing state-of-the-art inverter electronics with a 2-stroke engine – but in many ways it works.

Although the output isn’t as super-smooth as the Impax machine, it’s good enough to power all but the most sensitive devices directly.

The unit’s max output is 800W, and peak is 1000€€€W. Both are pretty staggering from a tiny generator that weighs in at 8.5kg and measures just 23 x 29 x 33‡‡cm.

There are drawbacks, though. It’s quite noisy, there isn’t a 12ƒV output, and the 3.5-litre tank won’t keep the unit running long at high outputs.

Osaki OSA-273-3000‘‡’‡€€€K – four stars

At first glance, this and SIP’s Tˆ951 look identical, apart from their colour schemes. But there are subtle di™fferences that make this the better machine, even before its bargain price is considered.

Like the SIP, max output is 650W (peak 800­€€W) at 230V. But max 12ƒV output is an impressive 8.3A – much like Clarke’s huge G1200. And that’s one thing this generator isn’t. At 36 x 35 x 33cm, it’s not as compact as the inverter models, but it is easily stored.

The 2-stroke engine is gutsy, if not especially frugal. And at 87dBA, it’s quieter than many units here.

Champion 71001I Inverter 1000W – three stars

Champion is America’s most popular generator brand, and this machine offers something di­fferent to most.

Its best features are its smooth pure sine output and low-noise operation. Even compared with the muted Impax and Clarke IG1200, this is significantly quieter: probably much more than the 73 versus 93dBA ratings suggest.

And we love the design. All controls are neatly grouped together, and you can even run two of these, in tandem, stacked on top of each other.

But for the 900W output (1000W peak) on offer, the unit seems expensive, a bit big (‡45 x 27 x 40cm), and somewhat heavy (16.3kg). The lack of 12V charging is also a drawback.

Clarke G1200 – three stars

Unlike most of the conventional – non-inverter – generators here, this has a 4-stroke engine. And, in theory, that should be a good thing.

In practice, though, the unit seems just as loud as its 2-stroke cousins, but somehow lacks their smoothness. This is further backed up by our voltage tests.

Obviously, output isn’t as well controlled as the inverter models, but it seemed a little more wayward than the conventional 2-strokes, too.

We like the max output of 1000W (1100W peak), and the punchy 8.3A available at 12V. But at 44 x 33 x 37cm, and weighing 25kg, this is one cumbersome piece of kit to lug around.

Clarke IG1200 – five stars

Practical Motorhome Editor’s Choice

This is a reasonably new machine and one that’s already become a firm favourite with all branches of the camping fraternity.

That’s partly because the 1000W max output (1200W peak) easily exceeds the output of 4A hook-up, allowing more comfortable off-grid touring. But, much like Impax’s IM„800i, this is also a very easy machine to live with.

The 93dBA sound level doesn’t seem much of an improvement over the louder machines’ 95dBA ratings, but the noise produced is far less raucous.

Other similarities with the Impax include impressive e‰fficiency and sensible weight (12.4kg) but, again, it has a disappointingly low 12V output of just 4A.