NOCO GB40 vs GB50

The GB50 is the quietest product in NOCO's Boost range. It gets less attention than the GB40 below it and the GB70 above it, and it has no review page of its own anywhere on this site, which is exactly why it is worth a page: on paper it is the best value in the lineup, and on paper is also where its problem lives, because the GBX45 sits in almost the same place for a different reason.

This page is the narrow question. If your decision is really "compact pack or diesel pack," read GB40 versus GB70 instead — that is the big either/or, and the engine ratings settle it quickly. What follows is for people who have already decided they want a compact lithium pack and are now staring at three of them.

Going from the GB40 to the GB50 costs you 0.26 lb — about the weight of a phone — and buys three things NOCO publishes: 500 more peak amps, 11 more watt-hours of stored energy, and a full extra liter of gas engine rating. The flashlight also doubles from 100 to 200 lumens, which sounds like a throwaway spec until you are under a hood at night.

Of those, the engine rating is the one that should drive the decision, because it is NOCO's own statement about what the pack is for. Peak amps is a headline figure measured under conditions nobody can reproduce roadside; the liter rating is the manufacturer translating that into something you can check against your own car. Peak amps versus cranking amps explains why we weight it that way.

The 11 extra watt-hours matter in a second-order way: more stored energy means more starting attempts before the pack needs a recharge. On a warm day with a healthy battery you need one attempt. On a cold morning with a tired battery you might need three, and that is the scenario the capacity is for. Will a jump starter start a dead battery covers when more attempts help and when they do not.

Find your engine's displacement and fuel type on the label under the hood or in the manual, then find your line:

• Gas, up to about 5.0 L — GB40. You are well inside its 6.0 L rating with margin to spare, and the smaller, lighter pack is the one that stays in the car.
• Gas, 5.0 to 6.0 L — GB50, if you want margin. The GB40 covers it on paper; the GB50 means you are not sitting at the ceiling on the worst morning of the year.
• Gas, 6.0 to 7.0 L — GB50. A 6.2 L V8 is past the GB40's published rating, and this is the lightest pack in the range that covers it.
• Gas, above 7.0 L — neither. That is GB70 territory, at an 8.0 L rating.
• Diesel, up to 3.0 L — the GB40 covers it on paper and we would still buy the GB50. A small diesel at the GB40's exact ceiling has nothing left in reserve.
• Diesel, 3.0 to 4.5 L — GB50. This is the clearest case in the whole comparison.
• Diesel above 4.5 L, or any full-size diesel pickup — neither. Buy the GB70 and stop reading. The best jump starters for diesel trucks is the page for that.

If this were just GB40 against GB50, the GB50 would win most of the arguments. It is not, because the GBX45 covers 6.5 liters of gas and 4.0 liters of diesel at 2.16 lb — lighter than the GB40, let alone the GB50 — and recharges over USB-C Power Delivery in both directions, so it takes the same brick as a modern laptop and will charge a phone back.

That reshapes the decision into two different questions rather than one. If what you want is amps and diesel rating, the GB50 is ahead: 1,500 A and 4.5 L diesel against 1,250 A and 4.0 L. If what you want is a pack that travels, the GBX45 is ahead on every axis that matters for travel — weight, charging and packed size. GBX45 versus GB40 takes that comparison on its own terms, and the best jump starter for travel is the wider field.

Our honest read: the GB50 is the better buy for a vehicle that stays in one region and might be a truck; the GBX45 is the better buy for a person who flies, drives rentals, or wants one charger for everything. The GB40 remains the right answer for the large middle of the market — a gas four or V6 that lives near home.

All three are IP65-rated, though NOCO qualifies the GBX45's rating as holding with the port covers closed. All three carry NOCO's reverse-polarity protection, which is the real safety advantage over jumper cables and the reason a backwards clamp does not produce a shower of sparks. All three carry the same one-year hassle-free warranty.

And all three are comfortably under the FAA's 100 watt-hour carry-on threshold at 24, 35 and 31 watt-hours, so none of them is harder to fly with than the others. Lithium jump starters must travel in carry-on rather than checked baggage, which is a rule about the chemistry and not about these particular models. Flying with a jump starter has the detail.

1. 1Your engine is nowhere near the ceiling. A 2.0 L four-cylinder does not care that the GB50 could start a 7.0 L V8. Buying headroom you will never draw is paying for a number.
2. 2Size is the feature. 2.45 lb goes in a door pocket or a seat-back organizer. The reason people end up stranded next to a jump starter is that the jump starter is in the garage, and the smallest pack that covers your engine is the one most likely to be in the car.
3. 3It is the most common pack in the range, which means accessories, cables and replacement clamps are easy to find. That is a small thing until you need it.

First, if you drive a diesel pickup. Both of these packs are below what a 6.7 L truck engine wants, and buying at the edge of a rating is how people end up stranded twice. Second, if your battery is the actual problem rather than your luck. A pack that gets used monthly is a pack papering over a failing battery, and the fix is a charger or a replacement. How to tell if a car battery is bad is the five-minute test, and the best car battery chargers is the other half of the answer.

1. Enough for most drivers

NOCO Boost Plus GB40

NOCO · Best for most cars and small suvs

The default answer for a four- or six-cylinder car: 1,000 peak amps, 24 watt-hours, and light enough that it actually stays in the trunk.

Published specifications

Peak amps

1,000 A source

Internal battery

24 Wh lithium-ion source

Gas engine rating

Up to 6.0 liters source

Diesel engine rating

Up to 3.0 liters source

Weight

2.45 lb (1.11 kg) source

Water resistance

IP65 source

Flashlight

100 lumens source

Warranty

1-year hassle-free source

What works

• +24 Wh sits far under the 100 Wh carry-on threshold, so flying with it needs no airline approval
• +2.45 lb and pocketable — the size that decides whether a tool is still in the trunk six months later
• +IP65 enclosure, so a wet shoulder in the rain is not a problem
• +Reverse-polarity protection means a backwards clamp does not spark

What does not

• −1,000 peak amps runs out of headroom above a 6.0 L gas engine
• −The 3.0 L diesel ceiling rules out most modern diesel pickups
• −24 Wh is a small reserve — it is a jump starter, not a power bank substitute

Skip it if

Not the one to buy if you drive a diesel pickup or a big V8. You would be at the edge of its rating on a cold morning, which is exactly when you want margin.

$99.95·View on Amazon→

#ad Affiliate link · Price as of October 16, 2026

Raw specifications: NOCO’s own page for the NOCO Boost Plus GB40.

2. The cheapest headroom in the range

NOCO Boost Plus GB50

NOCO · Best for v6 and small v8 gas engines

The middle rung: 1,500 peak amps and 35 watt-hours for a quarter-pound more than the GB40, which is the cheapest headroom in the range.

Published specifications

Peak amps

1,500 A source

Internal battery

35 Wh lithium-ion source

Gas engine rating

Up to 7.0 liters source

Diesel engine rating

Up to 4.5 liters source

Weight

2.71 lb (1.22 kg) source

Water resistance

IP65 source

Flashlight

200 lumens source

Warranty

1-year hassle-free source

What works

• +A full liter more gas headroom than the GB40 for 0.26 lb more weight
• +35 Wh still clears the 100 Wh carry-on limit with room to spare
• +Doubles the flashlight output over the GB40 at 200 lumens

What does not

• −Overlaps awkwardly with the GBX45, which is lighter and charges over USB-C
• −Still short of the 6.0 L diesel rating a modern diesel pickup wants

Skip it if

Skip it if convenience matters more than amps — the GBX45 is lighter and takes USB-C Power Delivery, and the GB50's edge is raw current.

$149.95·View on Amazon→

#ad Affiliate link · Price as of October 16, 2026

Raw specifications: NOCO’s own page for the NOCO Boost Plus GB50.

3. The option that complicates the choice

NOCO Boost X GBX45

NOCO · Best for travel and carry-on use

The travel pick: 1,250 peak amps at 2.16 lb with USB-C Power Delivery in and out, so it recharges from the same brick as your laptop.

Published specifications

Peak amps

1,250 A source

Internal battery

31 Wh lithium-ion source

Gas engine rating

Up to 6.5 liters source

Diesel engine rating

Up to 4.0 liters source

Weight

2.16 lb (0.98 kg) source

USB-C output

Up to 20 V / 3 A Power Delivery source

Water resistance

IP65 with ports closed source

Warranty

1-year hassle-free source

What works

• +Lightest pack in the range at 2.16 lb, and 31 Wh means no airline paperwork
• +USB-C Power Delivery both directions — one cable covers the pack, phone and laptop
• +More gas headroom than the GB40 (6.5 L against 6.0 L) in a lighter body

What does not

• −The IP65 rating only holds with the port covers closed — worth remembering in the rain
• −The 4.0 L diesel ceiling is not enough for a full-size diesel pickup

Skip it if

Not the right pack for a diesel truck, and not the cheapest way to cover a small commuter — its premium buys packability, not amps.

$124.95·View on Amazon→

#ad Affiliate link · Price as of October 16, 2026

Raw specifications: NOCO’s own page for the NOCO Boost X GBX45.

Whichever you buy, keep it charged and keep it in the car. NOCO's packs hold charge well, but a lithium pack left in a hot trunk for two summers is not the pack you bought — jump starter storage and heat covers what that costs, and how to charge a jump starter covers the maintenance habit. If winter is your concern, the cold-weather tire inflator roundup is the other tool the same mornings call for.