NOCO Boost X GBX155 jump starter review

Overview

The NOCO Boost X GBX155 is a premium portable jump starter aimed at drivers who need more starting capacity than a typical car-focused pack offers. The listing rates it at 4,250A and claims compatibility with petrol engines up to 10.0L and diesel engines up to 8.0L. It ranks #10 in our list of the top 10 best-selling portable jump starters on Amazon UK, with a Garage Ten score of 8.2/10 and an award for Best for very large engines. Its headline figures make it more specialised than the GBX55, which we highlight for motorhomes, and the GB150, our pick for farm and workshop use: choose the GBX155 when the largest stated engine capacity is your priority, rather than simply buying the biggest pack for an everyday car.

Features and specification

The GBX155 is a 12V lithium-ion booster with spark-proof and reverse-polarity protection. The listing says it can deliver up to 18 starts per charge, although actual results will depend on the vehicle, battery condition and circumstances. It also claims that five minutes of charging can provide enough power for a jump start, and that a full recharge takes 2.7 hours with a 60W USB-C Power Delivery charger. That charger is not included, so check what you already own before relying on the fastest recharge times.

USB-C PD output supports charging phones, tablets and laptops, while the 500-lumen torch has seven modes, including SOS and strobe. The box includes jump leads, a USB-C cable, a 12V in-car charging cable and a fabric storage bag. At around 3.2kg, it is substantial for a portable unit, and there is no hard case in the listed contents. Independent reviewers at Popular Mechanics found the GBX155 quicker to charge than the Gooloo GT6000, while noting that the rival offers higher stated output and more ports; that is a useful reminder to weigh the whole package, not just the amp figure.

What owners say

Many owners describe reliable starts on larger vehicles, including vans, diesel cars and tractors, and appreciate the USB-C charging and bright torch. Some also like that the unit can hold charge between occasional uses. These reports make it appealing for fleet, agricultural and workshop settings where a failed start can be particularly inconvenient.

There are less reassuring accounts too. Some frequent users report charging faults, including ports failing, while other buyers describe the unit losing charge or not retaining it as expected. A few also mention that it is bulky and would benefit from a sturdier case; others are disappointed that a suitable fast wall charger is an extra purchase. Experiences are mixed, so keep the warranty details and proof of purchase, and check the unit’s charge before depending on it.

Who should buy it

Consider the GBX155 if you regularly deal with large petrol or diesel engines, manage a fleet, or need a booster for agricultural or workshop equipment. Its high stated capacity and useful USB-C output are compelling on paper, provided you are comfortable with its size and premium positioning.

For an ordinary small car, occasional emergency use or a lightweight kit, it is likely more than you need. Is the NOCO Boost X GBX155 worth it? It can be, for large-engine users who value substantial output, but buyers prioritising lower cost, compactness or consistently reassuring reliability reports should compare smaller options in our list first.