NOCO GB40 review
NOCO Boost GB40 1000A Lithium Jump Starter
By Tom Calder
Key specs
The maker's figures.
- Peak amps (maker)
- 1,000 A
- Weight
- 2.5 lb
- Notes
- Recharges in about 3 hours
A 2.5 lb lithium pack that starts most car engines and lives in the glovebox, from the brand most often recommended for jump packs.
- Best for
- The glovebox jump starter for most cars
- Skip it if
- You drive a large diesel truck
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Researched, not used. We haven't used this product. This review is built from the maker's specifications, owner reports and our own sizing.
What we like
- Small and light
- Trusted brand
Worth knowing
- 1,000 A may struggle with big diesels
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Our review
The NOCO Boost Plus GB40 is a 1,000-amp lithium jump starter that NOCO rates for gas engines up to 6 liters and diesels up to 3 liters, weighing 2.45 lb with a 24 Wh battery, a 100-lumen flashlight and an IP65 rating. This researched review reads NOCO's product and spec pages, explains what it will and will not start, and covers the habits that keep it ready in a glovebox.
What NOCO lists
NOCO's page describes the GB40 as a portable lithium-ion jump starter that delivers 1,000 amps for starting a dead battery in seconds, designed for cars, boats, RVs and trucks with gas engines up to 6 liters and diesel engines up to 3 liters. The spec page lists 1,000 A peak, a 24 Wh lithium-ion internal battery, a USB-C input at 5 V and 2.1 A, a weight of 2.45 lb (1.11 kg), an IP65 rating and a 1-year hassle-free limited warranty. The box includes a USB-C to USB-C cable and a microfiber storage bag.
NOCO says it is for 12-volt lead-acid batteries only. That covers almost every car, truck and boat starter battery, but not the 12-volt lithium batteries in some motorcycles and the high-voltage packs in EVs; an EV's small 12-volt accessory battery is usually fine, but check the vehicle's manual.
Safety features
NOCO's page says the GB40 is spark-proof with reverse polarity protection, so clamping it the wrong way round does nothing rather than something dramatic. That mistake-proof design is the main reason to buy a modern lithium pack over cables and a second car: there is no stranger's alternator in the loop and no risk from touching clamps together.
It still needs a charged pack to work. NOCO says the USB port recharges it in 3 hours at 2.1 A, and the pack's own flashlight and phone-charging drain it, so charge it every few months and after every use. Lithium cells also dislike heat, so a car parked in Phoenix sun all summer is a hard home for it; our lithium battery fire safety guide covers storage.
Flashlight and phone charging
The built-in LED flashlight is rated at 100 lumens with seven modes including SOS and an emergency strobe. NOCO says the USB output gives up to four smartphone recharges, which makes the GB40 a small power bank for the car as well as a jump starter, though the 24 Wh cell is modest; for days without power you want a proper power bank.
It belongs in the winter car emergency kit alongside the blanket, the shovel and the snacks; Ready.gov's car kit lists jumper cables, and this does the same job without a second vehicle.
Limits
A 1,000-amp pack is sized for ordinary cars and small trucks. NOCO's engine limits (6 L gas, 3 L diesel) rule out most full-size diesel pickups and large SUVs, and a very cold morning cuts a lithium pack's output, so a vehicle at the top of the range may need a second try. NOCO's spec page does not give an operating temperature range in text we could verify, so treat deep-winter performance as unproven.
A deeply discharged battery can also be too far gone for any jump pack to help, and a battery that needs jumping twice in a month needs replacing, not another jump.
How it compares, and who should skip it
The NOCO Boost HD GB70 doubles the peak current to 2,000 A, extends the engine range to 8 L gas and 6 L diesel, and adds a 400-lumen light, at 4.18 lb and a longer recharge. For a sedan, crossover or small pickup the GB40 is the right size; for a diesel truck, buy the GB70. Our jump starter comparison lists both.
Skip the GB40 if you drive a large diesel or a big-block gas engine, if your vehicle has a 12-volt lithium battery (check the manual), or if you want a pack that doubles as a serious power bank.
A researched review, built from the maker's specs, manual and US listings; facts checked 2 Nov 2026. Sources: NOCO: GB40 1000A 12V Boost Plus UltraSafe jump starter product page; NOCO: GB40 specifications.
Who shouldn't buy this
Don't buy it if you drive a large diesel truck: look at the GB70.
This is a Researched review: we haven't used this product. We check every specification against at least two independent sources, re-check the US price on a schedule where we can track it automatically, and say plainly who it isn't for. Commissions never change a rating.
If this isn’t the one
Best for For trucks, SUVs and bigger engines
Read the review →Best for The pro-style box mechanics use
See the comparison →Questions
What engines will the NOCO GB40 start?
NOCO rates it for gas engines up to 6 liters and diesel engines up to 3 liters, with 12-volt lead-acid batteries only. Larger diesels need the GB70.
How long does it take to recharge?
NOCO says 3 hours from any powered USB port at 2.1 amps through its USB-C input. Recharge it after every use and top it up every few months in storage.
Is it safe if I connect the clamps backwards?
NOCO says the GB40 is spark-proof with reverse polarity protection, so a wrong connection does nothing. Correct the clamps and try again.
Can it charge my phone?
Yes, through its USB output; NOCO says up to four smartphone recharges from the 24 Wh battery. Every charge you take reduces what is left for the jump start.