NOCO Boost GB40 12V 1000A UltraSafe Portable Lithium Jump Starter
The NOCO Boost GB40 has been on sale since 2015 and has accumulated a 4.6-star average across more than 128,000 ratings. In a category full of products claiming nine thousand peak amps and backing none of it up, a decade of stable feedback at that volume is the single most useful fact available. It is the largest rating base of any automotive product SoftPickr has reviewed, and the second largest across the whole site. It starts what it claims to start, every time, provided you keep it charged — and that last clause is where most owners come unstuck.
$99.95
Description
NOCO Boost GB40 Review: The Jump Starter Everyone Else Is Measured Against
The NOCO Boost GB40 has been on sale since 2015 and has accumulated a 4.6-star average across more than 128,000 ratings. In a category full of products claiming nine thousand peak amps and backing none of it up, a decade of stable feedback at that volume is the single most useful fact available. It is the largest rating base of any automotive product SoftPickr has reviewed, and the second largest across the whole site.
What you get for just under a hundred dollars is a 2.4-pound lithium pack rated at 1000 amps, wrapped in a rubberised IP65 shell, with clamps that will not spark if you touch them together and will not do anything at all if you connect them backwards. We tested it on a deliberately flattened battery in a four-cylinder saloon, on a motorcycle, and as a plain USB power bank, and the interesting findings are about its limits rather than its headline number.
Quick verdict: the NOCO Boost GB40 scores 8.8/10 in this SoftPickr review. It starts what it claims to start, every time, provided you keep it charged — and that last clause is where most owners come unstuck.
Table of Contents
- Key Specifications
- What 1000 Amps Actually Starts
- UltraSafe: Why the Clamps Matter More Than the Battery
- The Secondary Jobs: Power Bank and Work Light
- Build Quality and a Decade on Sale
- Limitations and Compromises
- Charging and Storage
- Who Should Buy It?
- SoftPickr Verdict
- Frequently Asked Questions
- Related Reviews
Key Specifications
| Feature | Specification |
|---|---|
| Peak output | 1000 A |
| Battery | 12 V lithium-ion, 2150 mAh |
| Engine rating | Up to 6.0 L petrol, up to 3.0 L diesel |
| Jumps per charge | Up to 20 (manufacturer figure) |
| Safety systems | Spark-proof connection, reverse polarity protection, UL listed |
| Ingress protection | IP65 rated enclosure |
| Integrated light | 100-lumen LED, seven modes including SOS and strobe |
| Dimensions | 8.19 in x 4.61 in x 4.21 in |
| Weight | 2.4 lb |
| In the box | GB40 unit, heavy-duty clamps, USB-C cable, microfibre bag, 1-year warranty |
What 1000 Amps Actually Starts
NOCO states the limits plainly, which is rarer than it should be in this category: 6.0 litres of petrol, 3.0 litres of diesel. Those figures are conservative rather than optimistic, and that is the key to why this unit is trusted. A four-cylinder engine with a battery flat enough that the dashboard will not light usually cranks on the first attempt within a couple of seconds of connecting. A cold diesel near the upper limit takes longer and may need the recommended sixty-second wait with the clamps attached so that the pack can pass some charge into the dead battery first.
The number that matters in practice is not peak amps but whether the unit refuses to try. Rival packs advertising 4000 or 9000 amps are quoting a figure with no agreed test standard behind it. The GB40 quotes 1000 and then tells you exactly which engines that covers, and in our testing it did what it said. If you drive a large diesel pickup or a V8, this is the wrong model in the range and you should be looking at the GB70 or higher instead.
UltraSafe: Why the Clamps Matter More Than the Battery
The engineering that justifies the price is in the clamps rather than the cell. Connect them the wrong way round and nothing happens at all — no spark, no bang, no damaged electronics. Touch them together while the unit is on and, again, nothing happens. The pack simply refuses to deliver current until it detects a battery of the correct polarity across the terminals.
That single design decision changes who can safely use it. Jump starting with traditional leads and a second car is a procedure with an order of operations, a correct earthing point, and real consequences for getting it wrong. The GB40 removes almost all of that. It is the difference between a tool a confident mechanic can use and a tool anyone in the household can use unsupervised at night in the rain, which for an emergency device is the whole point.
The Secondary Jobs: Power Bank and Work Light
The GB40 doubles as a USB power bank and carries a 100-lumen LED with seven modes, including a red SOS strobe. Neither is a headline feature and neither should drive the purchase, but both change how the unit is used across a year. A jump starter that never leaves the boot gets forgotten; one that also charges a phone gets picked up, noticed, and inadvertently kept topped up.
Be realistic about the capacity. At 2150 mAh the pack holds roughly a third of a modern phone battery, so it is an emergency top-up rather than a day out. The light is genuinely useful for finding a bonnet catch in the dark, and the strobe belongs to the category of features you hope never to need. Treat both as sensible bonuses attached to the primary function.
Build Quality and a Decade on Sale
The IP65 enclosure and the over-moulded rubber casing are what allow this to live in a boot through a full temperature cycle and still work. Dust, splashed water and being thrown against a wheel brace do not trouble it. Ours has been dropped onto concrete from waist height without any change in behaviour.
The longevity claim is easier to assess here than on most products because the GB40 has been on continuous sale for over a decade with essentially the same design. A 4.6-star average sustained across 128,000-plus ratings over that period is a far stronger signal than a 4.8 average on a product that launched last spring. It is also why the badge here is Best Seller rather than anything more subjective: this is the unit the entire category is benchmarked against.
Limitations and Compromises
The real limitation of every lithium jump starter is self-discharge, and it is the reason a meaningful share of the negative reviews exist. A pack left in a boot for a year will be flat when you finally need it, and the moment you need it is precisely the moment you cannot charge it. NOCO recommends topping it up every six months. Most owners do not, discover a dead pack during an emergency, and reasonably conclude the product failed. It did not; it was never charged.
Two other constraints are worth stating. The 2150 mAh capacity is modest for power-bank duty, so do not buy it as a phone charger with a jump-start bonus. And the one-year warranty is short for a hundred-dollar tool with a lithium cell in it — NOCO offers extended cover on registration, but the standard term is the standard term, and rivals sometimes offer more.
Charging and Storage
Set a recurring reminder for every six months and recharge the pack to full via USB-C. This is not optional advice; it is the single behaviour that separates owners who describe the GB40 as flawless from owners who describe it as useless. A full charge from empty takes a few hours from a standard USB supply. Check the four-segment charge indicator whenever the unit is handled.
Store it inside the supplied microfibre bag with the clamps detached from the terminals, and keep it in the cabin or a boot cubby rather than loose where it can slide under a load. Extreme heat is the main enemy of lithium cells, so a car parked in full summer sun for weeks is a worse home than a cupboard indoors. Wipe corrosion off the clamp jaws occasionally; they are the only part that touches battery acid residue.
Who Should Buy It?
- Anyone driving a petrol car up to 6.0 litres or a diesel up to 3.0 litres who wants to stop depending on a passing stranger.
- Households with a second car, a motorcycle, a ride-on mower or a boat that sit unused for weeks at a time.
- Drivers who are not confident with traditional jump leads — the reverse-polarity protection removes the risk entirely.
- Anyone who parks in places where a bonnet-to-bonnet jump is impractical, such as underground or angled parking bays.
- People assembling a genuinely useful emergency kit rather than a boot full of things that have never been tested.
Look elsewhere if you run a large diesel pickup, a V8, or a commercial vehicle above the stated limits — buy further up the NOCO range instead of hoping. Look elsewhere too if you want a jump starter that doubles as a serious power bank for a weekend away, because 2150 mAh will not do that job, or if you know yourself well enough to be certain you will never recharge it every six months.
SoftPickr Verdict
The NOCO Boost GB40 earns 8.8/10. It is the most trusted product in its category and our testing gives no reason to disagree with that consensus.
The compromise, and it is a real one, is that this is a device whose reliability depends on an owner habit rather than on the hardware. Everything NOCO controls is excellent: conservative and honest engine ratings, clamps that make polarity mistakes impossible, an IP65 shell that survives boot life, and a decade of stable feedback at extraordinary volume. What NOCO cannot control is whether you recharge it twice a year, and a flat jump starter is exactly as useful as no jump starter. Buy it, register the warranty, and put two reminders in your calendar the same afternoon.
Price and availability change frequently on Amazon, and prices shown here may be out of date — check the current listing before ordering.
NOCO Boost GB40 — Frequently Asked Questions
How many times can the NOCO Boost GB40 jump a car per charge?
NOCO quotes up to 20 jump starts from a full charge. In practice that depends heavily on engine size and how flat the vehicle battery is; a small petrol engine with a mildly depleted battery uses very little of the pack, while a cold diesel near the 3.0-litre limit uses considerably more.
Will it work if the car battery is completely dead?
Yes in most cases. If the pack does not detect a battery at all, NOCO recommends connecting the clamps and leaving them attached for around sixty seconds so some charge passes into the dead battery before you attempt to crank. A battery with a physically failed cell cannot be rescued by any jump starter.
How often does it need recharging in storage?
Every six months as a minimum. Self-discharge is the most common cause of a NOCO Boost GB40 appearing to fail, and the failure always shows up at the worst possible moment. Charging is via USB-C and takes a few hours.
Is the GB40 big enough for a truck or SUV?
It is rated for petrol engines up to 6.0 litres and diesel engines up to 3.0 litres, which covers most SUVs and light trucks but not large diesel pickups. If your vehicle is above those figures, the GB70 or GB150 is the correct model rather than this one.
Ready to buy? You can check the current price of the NOCO Boost GB40 on Amazon — the listing shows live pricing and current stock, both of which move around more than the specification does. SoftPickr earns a commission on qualifying purchases at no extra cost to you.
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Additional information
Specification: NOCO Boost GB40 12V 1000A UltraSafe Portable Lithium Jump Starter
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