NOCO Jump Starters Across 3 Tests: One Was Underpowered

NOCO has become close to the default answer whenever someone asks for a jump starter recommendation, and across three separate hands-on tests spanning different NOCO models and different years, that reputation mostly holds up. Mostly, because one of the three tests found a specific NOCO unit underpowered for its price, and the honest version of this story includes that result too.

What the testing showed

The numbers below come from three of Project Farm's independent jump starter tests, spanning a 14-unit comparison, a 9-unit comparison, and an 8-unit portable comparison, each including at least one NOCO model. The full breakdowns are on the 14-unit jump starter test, the 9-unit jump starters test, and the 8-unit portable jump starters test.

The NOCO GBX155 won the largest test outright

In the most recent, largest test of 14 jump starters, NOCO's GBX155, at around 370 dollars, won with the best average finish of 1.6 across all graded categories. It delivered, in the test's own words, "by far the most current yet" on a V6 dead battery start, rated the best possible score in that category, and it started a big block 454 V8 with a nearly dead battery and no fuel in the tank in just over 10 seconds, the most powerful result recorded in that test. Notably, the reviewer had owned this exact unit for about 2 years before including it against newer competition and reported it "still performs as good as new."

The NOCO GB70 impressed in an older 9-unit test

A different NOCO model, the GB70 at 199.99 dollars, was tested in an earlier, separate 9-unit comparison. It posted 588 amps on the bench test, second best of all brands in that field, but delivered 13 seconds of sustained boost duration versus just 2 to 3 seconds for competing units, described as "by far the longest boost duration." In a real-world drained truck battery jump start it spun the engine over longer than any other brand tested, and it still performed well after an overnight freezer cold soak at 0F. Its one weak point was a power bank discharge test, where it delivered 43.4 Wh, "definitely not as good as some of the other brands despite its strong cranking performance."

The smaller NOCO GB40 was called out as underpowered for its price

In a separate 8-unit portable jump starter test, the NOCO Genius Boost Plus GB40, at 99.69 dollars, was the most expensive lithium-ion unit tested but did not perform to that price. On a real-world drained Ford Ranger pickup, it "did not produce enough voltage to spin the engine over," the cables got hot, and the unit showed an overheat indicator. It also failed to start a 1975 Ford 5000 diesel tractor, even after repeated attempts and a cold-soak retest. The test's own assessment: a "very high quality product overall but underpowered for its roughly $100 price," with an additional safety concern flagged about its thin carrying bag risking accidental activation in a trunk.

How to read this for your own purchase

The pattern across all three tests is that NOCO's larger, higher-capacity units performed at or near the top of their respective fields, while its smaller, lower-capacity GB40 model specifically struggled against real-world engine loads it was marketed to handle.

Capacity claims on the box did not match real-world results for the smaller unit

The GB40's own marketing claims 1,000 amps and the ability to start a 6 liter gasoline or 3 liter diesel engine, yet it only holds about 6,400 mAh of capacity, versus roughly 20,000 mAh for cheaper competitors tested in the same 8-unit comparison. That capacity gap lines up directly with its real-world failures on both the pickup truck and the diesel tractor starts, a useful reminder that peak amp claims on a jump starter's box do not always reflect the sustained capacity needed to actually turn over a stubborn engine.

If you need a jump starter for anything from a car to a diesel tractor or larger engine, the GBX155's result in the largest, most recent test and the GB70's strong real-world engine starts both point toward NOCO's higher-capacity lineup as the tested-strong choice.

Do not assume every NOCO model performs the same. The GB40 specifically underperformed against real dead batteries and a diesel tractor in its own test, despite being NOCO's most expensive entry in that particular comparison. Capacity, not just brand, predicted the outcome.

If longevity matters to you, the GBX155 test result is unusual in that it directly demonstrates 2-year real-world durability, since the reviewer had owned and used that specific unit before retesting it against newer competitors.

A rule that applies to any jump starter purchase: check the amp-hour capacity against the engine size you actually need to start, not just the brand or the claimed peak amps on the box. The GB40's underpowered result happened despite strong claimed specs on paper.

Browse the rest of the jump starters and car power tests for chargers, inflators, and power stations tested the same hands-on way.