Is the NOCO Boost GB40 Worth It in 2026?

NOCO's own page for the GB40 states it delivers 1,000 amps and is built for gas engines up to 6.0 liters or diesel engines up to 3.0 liters, with up to 20 starts per charge — the same figures the Amazon listing states. If your engine falls within those two ceilings, the GB40 is worth considering; if your engine is above either number, NOCO's own larger GB70 covers a wider range instead. NOCO's page also states the GB40 weighs 2.4 pounds and carries an IP65 enclosure rating, two figures the Amazon listing doesn't give.

Updated October 2026.

We did not test this product ourselves; this review is built from the manufacturer's published specifications and Amazon's product listing.

What Both Sources Say

Both the Amazon listing and NOCO's own page for the GB40 state the same core numbers: 1000 amps of starting current, a ceiling of 6.0 liters for gas engines or 3.0 liters for diesel engines on 12-volt systems, and up to 20 starts per charge. Both sources also describe the same two safety features — spark-proof operation and reverse-polarity protection — and the same secondary use as a power bank for personal devices.

NOCO's own page lists the GB40 as designed for "a car, boat, RV, truck and more" — a broad category list that, like the GB70's, doesn't by itself tell you whether your specific engine qualifies. The number that actually determines fit is the liter ceiling: a gas engine at or under 6.0 liters, or a diesel engine at or under 3.0 liters, is within the stated range.

What Only NOCO's Page States

NOCO's own page adds several figures the Amazon listing GarageRated reviewed doesn't mention. The unit is part of NOCO's Boost Plus line and weighs 2.4 pounds, per NOCO's page — lighter than the GB70's stated 5.0 pounds. It's housed in a water- and dust-resistant enclosure NOCO rates at IP65, wrapped in a rubberized over-molded casing. NOCO's page states the GB40 is good for up to 4 smartphone recharges per charge, and separately states the unit itself recharges from a powered USB port in about 3 hours at 2.1 amps — a figure the Amazon listing doesn't give. The built-in flashlight is rated at 100 lumens with seven light modes, including SOS and emergency strobe settings, per NOCO's page. NOCO describes the rubberized casing itself as designed "to prevent scratching or marring of surfaces" — relevant if you're setting the unit down on a hood or interior trim while you connect it.

NOCO's page doesn't mention a 12V output for the GB40 the way it does for the larger GB70 — it describes USB charging only, so don't assume a 12V output is included. NOCO's page also doesn't state a cable length or a warranty term, and its "What's in the Box" section didn't list specific contents when we read it.

Key Specs

Checking Your Engine Against the Ceiling

The two numbers that matter for fit are your engine's displacement in liters and whether it runs on gas or diesel, both typically listed in your owner's manual or on a label under the hood. If your gas engine is at or under 6.0 liters, or your diesel engine is at or under 3.0 liters, the GB40's stated ceiling covers it, per NOCO's own page and the Amazon listing. If either number is higher, NOCO's own GB70 states a wider ceiling instead — up to 8.0 liters gas or 6.0 liters diesel, per NOCO's page for that unit — though it also weighs more than twice as much, per NOCO's stated figures for each (2.4 lb vs 5.0 lb). If you don't already know your engine's exact displacement, it's usually printed in your owner's manual, on a build sticker under the hood, or on the manufacturer's own spec page for your specific vehicle and model year.

What Stands Out

• The engine-size ceiling is stated plainly, in liters. Per both the listing and NOCO's page, 6.0L gas or 3.0L diesel is the number to check against your own engine.
• It's the lighter of NOCO's two units covered on this site. 2.4 pounds, per NOCO's page, against the GB70's stated 5.0 pounds.
• It does more than jump a battery. Per NOCO's page, it also works as a power bank (up to 4 smartphone recharges) and includes a 100-lumen flashlight with seven modes, including SOS and emergency strobe.
• It recharges in a stated amount of time. About 3 hours from a powered USB port at 2.1 amps, per NOCO's page — a figure not given for the larger GB70.
• NOCO describes the spark-proof and reverse-polarity combination as a "mistake-proof design," per its own page — language aimed at reducing the risk of a bad connection when you're jumping a battery in the dark or in bad weather.

Where It Might Not Fit

• Engines above the stated ceiling aren't covered. A gas engine over 6.0 liters or a diesel engine over 3.0 liters is outside the range NOCO and the Amazon listing both state for this unit; NOCO's own GB70 states a higher ceiling instead.
• No 12V output is mentioned. NOCO's page describes USB charging for personal devices but doesn't state a 12V output the way it does for the GB70.
• No stated cable length or warranty term on either source GarageRated reviewed.

How It Compares to Other Jump Starters on This Site

Not sure how many amps or what liter ceiling your specific vehicle actually needs? This breakdown of amp ratings by engine size is worth reading before buying any jump starter, including this one. If you're planning to leave a unit in the car through a cold winter, this guide to choosing a jump starter for winter use — titled for that exact situation — is a reasonable next read.

Check the current price of the NOCO Boost GB40 on Amazon to see the current listing details.

FAQ

What's the largest engine the NOCO Boost GB40 can jump-start?

Per both NOCO's own page and the Amazon listing, it's rated for gas engines up to 6.0 liters or diesel engines up to 3.0 liters on 12-volt systems.

How much does the GB40 weigh?

NOCO's page states 2.4 pounds. That's the figure to compare directly against the GB70's stated 5.0 pounds if weight is part of your decision.

How long does the GB40 itself take to recharge?

NOCO's page states about 3 hours from a powered USB port at 2.1 amps.

Will the GB40 work on a diesel truck?

Only if the diesel engine is at or under 3.0 liters, per NOCO's stated ceiling for the GB40. NOCO's own GB70 states a higher 6.0-liter diesel ceiling instead, per NOCO's page for that unit, at roughly double the stated weight.

Does the GB40 have a 12V output like the GB70?

NOCO's page for the GB40 doesn't mention one — it describes USB charging for personal devices only. NOCO's page for the GB70 does state a 12V output. If a 12V output matters to your use case, the GB70's own page is where that function is confirmed, not the GB40's.

Check the current price of the NOCO Boost GB40 on Amazon

This jump starter is one of several roadside-power picks this site covers; see our full shortlist for the rest.

Sources

• NOCO — product page for the GB40 (no.co), accessed October 2026.
• Amazon product listing for the NOCO Boost GB40: 1000A UltraSafe Jump Starter, per GarageRated's cleaned copy of the listing.