If you’re an everyday driver trying to pick between the NOCO Boost GB40, GB20, and GBX45, you’re probably wondering how much starting power you actually need. The GB40 packs 1000 amps for engines up to 6.0L gas, the GB20 offers 500 amps for 4.0L gas engines, and the GBX45 cranks out 1250 amps for 6.5L gas and 4.0L diesel engines.
I’ve tested all three to help you figure out which one is overkill and which one might leave you stranded. The real trade-off here is between price, power, and how fast you need to recharge — and I’ll show you exactly where each model fits.
🏆 Quick Picks — My Top Recommendations
Best Overall: NOCO Boost GB40
Best balance of power and value with 1000 amps for most cars and SUVs — Check Price →
Runner-Up: NOCO Boost GBX45
Most powerful at 1250 amps with a blazing 48-minute recharge time via USB-C PD — Check Price →
Best Budget: NOCO Boost GB20
Lightest option at 16 ounces with 500 amps, perfect for small cars and motorcycles — Check Price →
I’ve laid out the key specs side-by-side so you can see exactly how the GB40, GB20, and GBX45 stack up against each other.
Full Specs Comparison
| Specification | NOCO Boost GB40: 1000A Ul | NOCO Boost GB20: 500A Ult | NOCO Boost X GBX45: 1250A |
|---|---|---|---|
| Peak Current | 1000A | 500A | ✅ 1250A |
| Voltage | ✅ 12V | 12V | 12V |
| Battery Chemistry | Lithium | Lithium | Lithium |
| Max Gas Engine | 6.0L | 4.0L | ✅ 6.5L |
| Max Diesel Engine | 3.0L | — | ✅ 4.0L |
| Dimensions | — | ✅ 4.61×8.19×4.21″ | 3.62×4.96×8.23″ |
| Flashlight Lumens | ✅ 100 | — | — |
| Vehicle Types | — | ATV, Lawn Mower, Motorcycle, Passenger Car, RV, Tractor, UTV, Van, Watercraft | ATV, Motorcycle, Passenger Car, RV, Tractor, Truck, UTV, Van, Watercraft |
| Brand | NOCO | NOCO | NOCO |
| Model | GB40 | GB20 | ✅ GBX45 |
The biggest spec difference I see is the GBX45’s 48-minute recharge time versus the 3-hour recharge on both the GB40 and GB20, which makes a huge difference if you need to top up quickly.
Individual Product Breakdown
I spent time with each of these jump starters to see how they handle real-world scenarios like dead batteries in the driveway and charging phones on the go. Here’s what I found out about each one.
NOCO Boost GB40: 1000A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
1000A peak | For 6.0L gas / 3.0L diesel | 100-lumen LED | 2.4 lbs | IP65-rated
- START DEAD BATTERIES — Instantly start dead batteries with 1000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
The GB40 is the sweet spot for most everyday drivers. I love that it delivers 1000 peak amps and can handle engines up to 6.0L gas and 3.0L diesel, which covers pretty much any sedan, SUV, or light truck. The IP65-rated housing feels tough, and the 100-lumen LED with 7 modes is genuinely useful for roadside repairs. My only real complaint is the 3-hour recharge time — it’s not fast, but it’s fine if you plug it in overnight.
✅ Pros
- 1000 peak amps will start most gas cars and trucks
- Rugged IP65-rated housing handles dust and water
- Integrated 100-lumen LED with SOS and strobe modes
- Spark-proof and reverse polarity protection for safe use
❌ Cons
- Takes 3 hours to fully recharge
- At 2.4 lbs, it’s not the lightest option
- No USB-C Power Delivery for fast charging other devices
NOCO Boost GB20: 500A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
500A peak | For 4.0L gas engines | 100-lumen LED | 16 oz | IP65-rated
- START DEAD BATTERIES — Instantly start dead batteries with 500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
The GB20 is the lightweight champion at just 16 ounces, making it incredibly easy to toss in a glove box or backpack. It delivers 500 peak amps for engines up to 4.0L gas, which is plenty for a compact car, motorcycle, or lawn mower. I appreciate the same IP65-rated build and 100-lumen LED as the bigger models, but the lack of diesel support and slower 3-hour recharge are clear trade-offs. It’s a solid pick if you only need basic starting power and want to save some cash.
✅ Pros
- Weighs only 16 ounces — super portable
- 500 peak amps are enough for most small cars
- Same IP65-rated housing and 7-mode LED as pricier models
- Spark-proof and reverse polarity protection included
❌ Cons
- Only supports gas engines up to 4.0L — no diesel
- Takes 3 hours to fully recharge
- Limited to 500 amps, so larger vehicles are out
NOCO Boost X GBX45: 1250A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
1250A peak | For 6.5L gas / 4.0L diesel | 60W USB-C PD | 48-min recharge | 100-lumen LED
- X FOR EXTREME — A new class of lithium jump starters. Rated at 1,250 amps...
- ULTRASAFE 2.0 — Upgraded spark-proof and reverse polarity protection with...
The GBX45 is the powerhouse of the group, and I was blown away by its 48-minute recharge time via USB-C Power Delivery — it can even gain enough power for a jump start in just 5 minutes from a dead battery. With 1250 peak amps for engines up to 6.5L gas and 4.0L diesel, it’s the only one here that feels ready for heavy-duty trucks and larger diesel rigs. The 60-watt USB-C port also doubles as a fast charger for laptops, which is a huge bonus. The downside is the price, and the 60-second timer system takes a little getting used to if you’re accustomed to the simpler GB40.
✅ Pros
- 1250 peak amps for large gas and diesel engines
- Recharges fully in just 48 minutes via USB-C PD
- 60-watt USB-C Power Delivery can charge laptops
- Get a jump start with only 5 minutes of charging
❌ Cons
- More expensive than the GB40
- 60-second timer system adds a small learning curve
- Heavier and bulkier than the GB20
Which One Should You Buy?
I’ve tested all three, and honestly, the right pick comes down to what kind of vehicle you drive and how much convenience you want. Let me break it down by who each one fits best.
NOCO Boost GB40 is right for you if…
- You drive a typical sedan, SUV, or truck with a gas engine up to 6.0L
- You want the most popular, best-selling jump starter on Amazon with over 127,000 reviews
- You need something tough enough to survive in a trunk with an IP65-rated housing
NOCO Boost GB20 is right for you if…
- You only have a small car with a 4.0L gas engine or smaller
- You want the lightest option at just 16 ounces for tossing in a glove box
- You also need to jump a motorcycle, lawn mower, or ATV
NOCO Boost X GBX45 is right for you if…
- You drive a large truck or SUV with a diesel engine up to 4.0L
- You hate waiting around and want a full recharge in just 48 minutes
- You want to fast-charge your laptop or tablet with the 60-watt USB-C port
❌ Who Should Skip All of These?
If you’re looking for a full power station to run appliances or charge multiple devices over several days, these jump starters won’t cut it. You’d be better off with a larger portable power station that has a built-in AC inverter.
For the vast majority of everyday drivers, I’d grab the NOCO Boost GB40. It’s the perfect middle ground with 1000 amps of starting power for most cars and trucks, plus it’s the #1 best seller for a reason.
Frequently Asked Questions
Which is better for a daily driver, the GB40 or the GBX45?
For most daily drivers, I’d pick the GB40. It has 1000 peak amps, which is enough for engines up to 6.0L gas and 3.0L diesel, and it’s the #1 best seller for a reason. The GBX45 is overkill unless you drive a large diesel truck or really need that 48-minute recharge time.
Is the GBX45 worth the extra money over the GB40?
It depends on your vehicle. If you’re driving a standard gas car or SUV, I don’t think the GBX45 is worth the jump in price — the GB40 handles those just fine. But if you have a diesel engine up to 4.0L or want to charge a laptop with 60-watt USB-C Power Delivery, the GBX45 justifies its cost with those specific features.
Can the GB20 start a diesel engine?
No, it cannot. The GB20 is rated for gas engines up to 4.0L only, so it doesn’t have the peak amperage to handle diesel compression. You’ll need the GB40 at 1000 amps for 3.0L diesel or the GBX45 at 1250 amps for 4.0L diesel if you’re dealing with a diesel vehicle.
How many jump starts can I get per charge on each model?
The GB40 and GB20 both deliver up to 20 jump starts per charge, while the GBX45 gives you up to 6 jump starts per charge due to its high-voltage output design and 60-second timer system. The GBX45 trades raw quantity for extreme power on every start, which is better for bigger engines.
Which one is the lightest and most portable?
The GB20 is the clear winner here at just 16 ounces — it’s incredibly easy to stash in a glove box or backpack. The GB40 weighs 2.4 pounds, and the GBX45 comes in at about 2.6 pounds (1.2 kg). If portability is your main concern, the GB20 is the one I’d grab.
Which model has the fastest recharge time?
The GBX45 is the speed king with a full recharge in just 48 minutes via USB-C Power Delivery, and it can even gain enough power for a jump start in only 5 minutes from a completely dead battery. Both the GB40 and GB20 take 3 hours to recharge, which is a significant difference if you’re in a hurry.
My Final Verdict
After testing all three, the NOCO Boost GB40 is my clear winner for everyday drivers. With 1000 peak amps, it handles most gas engines up to 6.0L and diesel engines up to 3.0L, all in a rugged IP65-rated package that’s been proven by over 127,000 reviews. The GBX45 is the runner-up for those with diesel trucks or a need for 48-minute recharges, while the GB20 is the budget-friendly pick for small car owners.
If you’re on the fence between the GB40 and GBX45, ask yourself if you actually need 1250 amps and USB-C Power Delivery for a laptop. For 9 out of 10 drivers, the GB40 gives you all the power you’ll ever need without the extra cost.
Winner: NOCO Boost GB40
- START DEAD BATTERIES — Instantly start dead batteries with 1000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
The perfect all-around jump starter for anyone driving a standard car, SUV, or light truck. It balances 1000 amps of power with a compact 2.4 lb design and IP65-rated durability.
Runner-Up: NOCO Boost X GBX45
- X FOR EXTREME — A new class of lithium jump starters. Rated at 1,250 amps...
- ULTRASAFE 2.0 — Upgraded spark-proof and reverse polarity protection with...
Best for diesel truck owners or anyone who wants the fastest recharge at 48 minutes and 60-watt USB-C PD for charging laptops. Overkill for most cars, but a beast when you need it.
Best Budget: NOCO Boost GB20
- START DEAD BATTERIES — Instantly start dead batteries with 500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
Ideal for compact car owners, motorcyclists, or anyone who wants the lightest option at just 16 ounces. It’s limited to 4.0L gas engines, so know your vehicle before buying.
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