The range's pocket format, designed for motorcycles and small petrol engines
The GB20 opens Noco's Boost range with a clear goal: covering the vehicles that the higher models handle in overkill. Its 500 A peak current restarts a petrol engine up to 4.0 L with a completely flat battery, which takes in almost the entire urban fleet, motorcycles, quad bikes, jet skis and ride-on mowers. The GB20 successfully starts a petrol vehicle with a weak battery, a straightforward result with nothing out of the ordinary.
The format genuinely fits under a motorcycle seat or in a door pocket, where a GB70 will not go. A jump starter you actually carry with you beats one left in the garage: that is this model's central argument.
No diesel: a ceiling sometimes confused online
Noco only certifies the GB20 for petrol, up to 4.0 L of displacement. No data found contradicts this ceiling, in either direction: it is a limit the manufacturer openly acknowledges rather than a grey area. The point actually worth watching lies elsewhere: several online comparison sites mistakenly confuse this ceiling with the GB40's, which does handle diesel up to 3.0 L. If your vehicle is a diesel, or a petrol engine above four litres, you need to move up to the GB40 or the GB50.
Charging cable: Micro-USB, not USB-C
Worth checking before buying: the GB20's charging input is Micro-USB (5V/2.1A), not USB-C. This is not a trivial detail: the more powerful GB50 does have USB-C, and this difference is sometimes blurred on third-party retailer listings that wrongly describe the GB20 as fitted with a USB-C port. Expect around 3 hours with a 2A charger, 6 hours at 1A, and up to 12 hours at 0.5A.
No independent test with published figures found for this specific model
Unlike the GB50, no German or English-language comparison with a described protocol has been found for the GB20: its internal battery, smaller than that of the models above it, places it below the capacity threshold that several comparisons consulted use for their selection. This is a genuine gap worth flagging honestly rather than filling in with an estimate: it reduces the confidence one can place in the stated endurance figures, without this amounting to a flaw in the product itself.
UltraSafe protection and manual override function
UltraSafe technology (clamps stay inert until the connection is correct, with active blocking in case of reverse polarity) works as expected, with a manual override function for situations where the unit needs to force the connection despite the detection. This is the same protection as on the rest of the range, with no compromise for this entry-level model.
Modest power bank function, room for improvement in the manual
The 24 watt-hour internal battery will bail out a phone, no more: the power bank function stays rather underpowered, just about enough for one smartphone charge. Another point, minor but real: the print on the supplied manual remains too small for comfortable reading, even though the basics of handling the unit stay intuitive.
Observed price and availability
The observed price for the GB20 sits around £72, the lowest in the Boost range. Official distribution of the model on the Japanese market remains uncertain: it does not appear on the official distributor's page that lists the higher models in the range, unlike the GB50.
Against the GB50: the choice comes down to fuel and budget
The reasoning is simple and comes down to one question: is your vehicle a diesel?
| Criterion | Noco GB20 | Noco GB50 |
|---|---|---|
| Peak current | 500 A | 1500 A |
| Petrol | Up to 4.0 L | Up to 7.0 L |
| Diesel | Not certified | Up to 4.5 L |
| Charging cable | Micro-USB | USB-C |
| Observed price | ≈ £72 | ≈ £106 |
If you only own a small-displacement petrol vehicle, a motorcycle or a leisure vehicle, the GB20 does the job for about £34 less and in a noticeably more portable format. As soon as a diesel enters the garage, it becomes unsuitable and the GB50 takes over, in exchange for a heavier unit and a switch flaw identified on that higher model, with nothing as clear-cut reported on the GB20.
Who it suits, and who it does not
It suits anyone with a petrol city car, a motorcycle, a quad bike or a leisure vehicle, looking for the most honest entry ticket into UltraSafe safety without paying for power they do not need.
It does not suit anyone with a diesel, even a small-displacement one, nor anyone looking for a serious power bank function for anything beyond the occasional phone top-up.
