Jump Starters
NOCO GB40 vs GB70
Same family, same protection, double the amps and nearly double the weight. Your engine picks the winner for you.
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How we assessed these: this comparison is built from manufacturer specifications and current retailer listings, not from hands-on testing of every unit. Figures we cannot source, we leave out.
Short answer
Buy the GB40 for a gas engine up to 6.0 liters — most cars and crossovers. Buy the GB70 for a diesel up to 6.0 liters, a gas engine up to 8.0 liters, or when you want cold-weather margin. The GB70 is 1.7 lb heavier for headroom a small engine will never draw.
These two packs are the ends of the decision most buyers are actually making. Both are NOCO Boost units with the same reverse-polarity protection and the same IP65 rating, so the question is not quality — it is whether your engine needs 1,000 peak amps or 2,000.
The specs, side by side
| Specification | GB40 | GB70 |
|---|---|---|
| Starting current | 1,000 A peak | 2,000 A peak |
| Internal battery | 24 Wh | 56 Wh |
| Gas engine rating | Up to 6.0 L | Up to 8.0 L |
| Diesel engine rating | Up to 3.0 L | Up to 6.0 L |
| Weight | 2.45 lb | 4.18 lb |
| Flashlight | 100 lumens | 400 lumens |
| Accessory output | USB only | USB plus 12 V, 15 A |
| Fast recharge | 3 h at USB 2.1 A | 3 h at 12 V / 3 A |
| Water resistance | IP65 | IP65 |
| Warranty | 1 year | 1 year |
| Flies in carry-on | Yes (24 Wh) | Yes (56 Wh) |
Figures from NOCO's own GB40 and GB70 specification pages, linked below.
The rule that decides it
Read your engine's displacement and fuel type, and find the side of this line you are on:
- Gas, under 6.0 L — GB40. That is most four-cylinders, every mainstream V6, and small V8s. The GB40 has margin.
- Gas, 6.0-8.0 L — GB70. A 6.2 L V8 is past the GB40's rating.
- Diesel, under 3.0 L — the GB40 technically covers it, and we would still buy up. A 3.0 L diesel at the GB40's exact ceiling has nothing left for a cold morning.
- Diesel, 3.0-6.0 L — GB70. This is the pack's whole reason for existing.
- Cold climate, any engine — one step up from the above. Cold cuts what the battery delivers and raises what the engine demands at the same time.
What 1.7 lb buys, and what it costs
The GB70's extra weight is not only the bigger battery. It is longer, heavier-gauge cables that actually reach a truck battery; a 400-lumen light instead of 100; and a 12 V, 15 A accessory output that will run a tire inflator directly from the pack. Those are real features, and on a truck they are the difference between a five-minute job and an awkward one.
What it costs is the property that makes a jump starter get used. A 2.45 lb pack lives in a door pocket or a seat-back; a 4.18 lb pack wants a dedicated trunk spot, and packs that want a dedicated spot are the packs that end up on a garage shelf. If your engine does not need the amps, the GB40's size is a feature and not a compromise.
What is identical, and therefore not a tiebreaker
Both are IP65. Both carry NOCO's reverse-polarity protection, which is the main safety advantage over jumper cables. Both carry the same one-year warranty. Both recharge in about three hours. And — usefully — both are under the FAA's 100 Wh carry-on threshold, so neither is easier to fly with than the other. See flying with a jump starter.
The third option nobody mentions
If you are stuck between them, the GB50 sits in the gap: 1,500 peak amps, 35 Wh, 7.0 L gas and 4.5 L diesel, at 2.71 lb. It is a quarter-pound heavier than the GB40 for a full extra liter of gas headroom, which is the cheapest margin in the range. It is the right answer for a 6.2 L gas V8 specifically. The GBX45 is the other in-between option, and it wins on weight and charging rather than on amps.
The picks
1. Pick this for a gas four or V6
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
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.
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Raw specifications: NOCO’s own page for the NOCO Boost Plus GB40.
2. Pick this for a diesel or big V8
NOCO Boost HD GB70
NOCO · Best for diesel pickups and big v8s
The one to buy if you drive a diesel: 2,000 peak amps, a 6.0-liter diesel rating and 56 watt-hours, which is the smallest pack with real margin on a cold diesel.
Published specifications
What works
- The 6.0 L diesel rating covers the common 3.0 L and 6.7 L light-truck diesels with margin
- 56 Wh is still comfortably under the 100 Wh carry-on threshold, so it flies as hand luggage
- 12 V 15 A accessory output, and a 400-lumen light that is genuinely usable roadside
- 12 V / 3 A fast charge brings it back in about three hours
What does not
- 4.18 lb — noticeably heavier than the compact packs, and it wants a dedicated spot
- Overkill for a commuter four-cylinder; you are paying for headroom you will not use
Skip it if
Not the one to buy if you only ever start a four-cylinder commuter. Buy diesel headroom when you have a diesel.
#ad Affiliate link · We show no price here; Amazon shows the current one
Raw specifications: NOCO’s own page for the NOCO Boost HD GB70.
Key takeaways
- GB40 for gas under 6.0 L; GB70 for diesel up to 6.0 L or gas up to 8.0 L.
- The GB70's extra 1.7 lb also buys longer cables, a 400-lumen light and a 12 V output.
- Neither is easier to fly with — both are under the 100 Wh limit.
- In a cold climate, buy one step up from your engine's minimum.
- If you are torn, the 1,500 A GB50 splits the difference for a quarter-pound.
How we sourced this
Every figure on this page came from one of the following. Where a manufacturer or regulator does not publish a number, we say so rather than estimate it.
Common questions
- Is the NOCO GB70 worth the extra money over the GB40?
- Only if your engine needs it. For a gas engine under 6.0 liters the GB40 already has margin, and the GB70's extra 1.7 lb buys headroom you will never draw. For a diesel above 3.0 liters, or a gas V8 above 6.0 liters, the GB70 is not an upgrade — it is the correct pack.
- Can the GB40 start a truck?
- A gas truck with an engine under 6.0 liters, yes — NOCO's rating covers it. A diesel pickup, no: the GB40's published diesel rating stops at 3.0 liters, which is well short of a 6.7 L truck engine.
- What is the difference in capacity between the GB40 and GB70?
- 24 watt-hours against 56 — the GB70 holds more than twice the energy. In practice that means more starting attempts before it needs a recharge, which matters most in cold weather when each attempt costs more.
- Should I buy the GB50 instead?
- It is a genuinely sensible middle option: 1,500 peak amps and a 7.0 L gas rating for 2.71 lb, a quarter-pound over the GB40. It is the right answer specifically for a 6.2 L gas V8 that does not need the GB70's diesel capability.
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Read next
Review
NOCO GB40 Review
1,000 peak amps, 24 Wh, 2.45 lb. The default answer for a four- or six-cylinder car — and wrong for a diesel.
Review
NOCO GB70 Review
2,000 peak amps, 56 Wh, 4.18 lb, rated to 6.0 L diesel. The right pack for a diesel pickup or a big V8.
Guide
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The sizing table by engine displacement and fuel type, using ratings manufacturers publish and warrant rather than peak-amp marketing.
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Found something out of date, or a figure you can source better than we did? Tell us — corrections get read first. Our methodology explains how picks are made, and contact is one click away.