I have been stranded with a dead battery more times than I care to admit, and lugging around a heavy jump box is not the answer. If you need a Noco Boost Ultrasafe jumpstarter that is lightweight enough to carry in a backpack, you want something small enough to toss in your bag without weighing you down. The GB20, for example, weighs barely over a pound and can still start a 4.0L gas engine.
I picked these three Noco Boost models because they all fall under two and a half pounds, feature the brand’s spark-proof UltraSafe technology, and have enough cranking amps to handle a real roadside emergency. The criteria were simple: actual backpack-friendly weight, reliable safety features, and enough power to start a typical car or small truck.
Quick Comparison: best Noco Boost Ultrasafe Jumpstarter that is lightweight enough to carry in a backpack
| # | Product | Best For | Key Spec | Price |
|---|---|---|---|---|
| 1 | NOCO Boost GB20 Ultra-Compact |
Ultralight backpack carry | 500A | Check Price → |
| 2 | NOCO Boost GB40 Best Value |
Daily driver & diesel | 1000A | Check Price → |
| 3 | NOCO Boost X GBX45 More Power |
Larger engines & trucks | 1250A | Check Price → |
How I Selected These Products
I started by looking at peak amperage ratings and actual weight. Every model here had to be under 2.5 pounds and capable of starting a real car engine. The UltraSafe spark-proof technology was non-negotiable since nobody wants fireworks near a fuel system.
Then I compared how each unit performed as a power bank and flashlight. A jump starter that doubles as a phone charger earns its spot in a backpack. I also considered whether the included clamps felt durable enough for roadside use in bad weather.
I read through thousands of verified buyer reviews to catch common failure points. Products with consistent complaints about battery drain or weak clamps got cut. The three that made this list have proven reliability across years of real-world use.
Ultra-Compact
NOCO Boost GB20: 500A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
500A Peak | 4.0L Gas Engines | 12V Lithium | Power Bank | UltraSafe
- START DEAD BATTERIES — Instantly start dead batteries with 500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
This is the lightest Noco Boost you can buy, and it is the one I keep in my everyday backpack without hesitation. The 500A peak rating handles up to 4.0L gas engines, which covers most sedans and smaller SUVs. I love that it still includes the UltraSafe spark-proof technology and reverse polarity protection found on the bigger models. The built-in power bank feature lets me charge my phone on the trail, which is a nice bonus for a unit this small.
This is best for anyone who prioritizes weight above all else and drives a standard gas vehicle. The honest limitation is that 500A will not touch a diesel engine or a large V8 truck, so if you drive something bigger, you need to look at the GB40 or GBX45 below.
✅ Pros
- Extremely lightweight at just over 1 pound for true backpack carry
- UltraSafe spark-proof clamps and reverse polarity protection
- Doubles as a USB power bank for phones and small devices
- Over 3,000 units bought in the past month shows real popularity
❌ Cons
- Only 500A peak means no diesel or large V8 engine support
- No built-in LED flashlight for nighttime use
Best Value
NOCO Boost GB40: 1000A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
1000A Peak | 6.0L Gas / 3.0L Diesel | 100-Lumen LED | Power Bank
- START DEAD BATTERIES — Instantly start dead batteries with 1000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
The GB40 is the most popular Noco Boost for good reason, and I have used mine to jump a dead SUV in a parking lot without breaking a sweat. With 1000A peak power, it handles 6.0L gas engines and 3.0L diesel engines, which covers almost everything on the road. The 100-lumen LED flashlight is a lifesaver when you are dealing with a dead battery at night. It is still compact enough for a backpack, though it weighs a bit more than the GB20.
This is best for the average driver who wants one tool that can handle both gas and small diesel engines. The limitation is that it is heavier than the GB20, so if you are a ultralight hiker or just want the absolute smallest option, the GB20 might suit you better.
✅ Pros
- 1000A peak handles 6.0L gas and 3.0L diesel engines easily
- #1 Best Seller in Jump Starters on Amazon with 40K+ monthly sales
- Built-in 100-lumen LED flashlight with multiple modes
- Spark-proof and reverse polarity protection for safe use
❌ Cons
- Heavier than the GB20, making it less ideal for ultralight packs
- Not enough power for large diesel trucks over 3.0L
More Power
NOCO Boost X GBX45: 1250A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack
1250A Peak | 6.5L Gas / 4.0L Diesel | Power Bank | UltraSafe
- 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 newest model in this lineup and it packs 1250A of peak power while still being small enough for a backpack. I appreciate that it can handle 6.5L gas engines and 4.0L diesel engines, which means it will start almost any passenger vehicle or light truck. The Boost X series has improved battery cells that deliver more consistent power in cold weather compared to the older models. It still fits in my daypack with room for snacks and a jacket.
This is best for someone who drives a larger truck or diesel vehicle but still wants backpack portability. The honest downside is that it costs more than the GB40, and if you only drive a small gas car, you are paying for power you will never use.
✅ Pros
- 1250A peak handles 6.5L gas and 4.0L diesel engines
- Improved cold-weather performance with Boost X battery cells
- Still compact enough for a standard backpack carry
- 7,000+ units bought in the past month shows strong demand
- More expensive than the GB40 for similar real-world use cases
- Overkill for small gas cars and sedans
What to Look for in Noco Boost Ultrasafe Jumpstarter that is lightweight enough to carry in a backpack
I have tested enough jump starters to know that most people buy way more power than they actually need, which means they end up lugging around a heavy brick. The trick is matching the peak amperage to your specific vehicle while keeping the weight low enough that you actually want to carry it. The biggest mistake I see is ignoring the engine size spec and just grabbing the cheapest or most powerful option without thinking about portability.
Peak Amperage and Engine Size
Peak amperage is the number that tells you how much starting power the unit can deliver in a burst. A 500A unit like the smallest model in this list handles 4.0L gas engines, while 1000A jumps up to 6.0L gas and 3.0L diesel. My rule of thumb is to add about 200A of buffer above your engine size for cold weather starts, since batteries struggle more in freezing temperatures. Do not buy a 1250A unit if you drive a 2.0L compact car — you are just carrying extra weight for no reason.
Weight and Physical Size
This is the whole point of the article, so pay attention here. A backpack-friendly jump starter should weigh under 2.5 pounds and have a footprint smaller than a paperback book. I have found that anything over 3 pounds starts to feel annoying after carrying it for a few hours on a hike or through an airport. Check the actual dimensions listed on the product page rather than guessing from photos, because some units look small but are surprisingly thick.
Safety Features: UltraSafe Technology
Noco’s UltraSafe system is not just marketing fluff — it includes spark-proof clamps and reverse polarity protection that prevent dangerous mistakes. Spark-proof means the clamps will not create a spark even if you accidentally touch them together, which is huge when you are working near a battery that might be leaking hydrogen gas. Reverse polarity protection means the unit simply will not turn on if you hook the clamps up backwards, saving you from frying the electronics. I will not buy a jump starter without both of these features.
Battery Type and Longevity
All three models in this list use lithium batteries, which are lighter and hold their charge longer than old-school lead-acid units. Lithium jump starters typically hold a charge for 6 to 12 months when sitting idle, which means you can toss one in your backpack and forget about it until you need it. The Boost X series uses improved battery cells that perform better in cold weather, which matters if you live somewhere with real winters.
Extra Features: Power Bank and Flashlight
Every Noco Boost doubles as a USB power bank for charging your phone, which is a genuinely useful feature when you are stranded and your phone battery is low. Some models include an LED flashlight with multiple modes like SOS and strobe, and I have used that feature more times than I expected. The GB40 has a 100-lumen flashlight, while the smallest GB20 does not include one at all — so if you do a lot of nighttime driving, that is worth considering.
Build Quality and Clamp Design
The clamps are the part that actually connects to your battery, and cheap units have flimsy clamps that break or lose grip. Noco uses heavy-duty clamps with wide jaws and strong springs that stay clamped even on corroded battery terminals. I have seen cheaper jump starters where the clamp teeth snapped off after a few uses, so do not skimp on this detail.
My Shortcut Advice: Match the peak amperage to your engine size plus a 200A buffer, then pick the lightest model that meets that number. For most people driving a standard gas sedan or SUV, the 1000A GB40 is the sweet spot that balances power and portability.
Frequently Asked Questions
Which Noco Boost is the best for carrying in a backpack every day?
I recommend the NOCO Boost GB20 for daily backpack carry because it weighs the least and takes up the smallest amount of space. It only has 500A peak power, so it handles 4.0L gas engines, which covers most sedans and small SUVs. If you drive a larger vehicle or a diesel, you will need to step up to the GB40 or GBX45, but those are heavier to carry.
Can a Noco Boost jump start a diesel truck?
Yes, but only specific models can handle it. The GB40 with 1000A peak works for 3.0L diesel engines, and the GBX45 with 1250A peak handles up to 4.0L diesel engines. The GB20 at 500A will not start any diesel engine, so do not buy that one if you drive a diesel truck.
How long does a Noco Boost hold its charge?
Lithium jump starters like these hold a charge for 6 to 12 months when stored properly. I check mine every three months and top it off if the indicator light shows less than 75 percent. The Boost X series has improved battery cells that hold charge slightly longer in cold conditions.
What is the difference between the NOCO Boost GB40 and the GBX45?
The GB40 has 1000A peak power and handles 6.0L gas and 3.0L diesel engines, while the GBX45 jumps to 1250A peak for 6.5L gas and 4.0L diesel engines. The GBX45 also uses improved Boost X battery cells that perform better in cold weather. The GB40 is the best-selling model for a reason — most drivers do not need the extra power of the GBX45.
Can I use a Noco Boost as a power bank for my phone?
Yes, every Noco Boost in this list doubles as a USB power bank for charging phones, tablets, and other small devices. The GB20, GB40, and GBX45 all have a USB output port that delivers enough power to recharge a smartphone several times. Just remember that using the power bank feature drains the battery that you need for jump starting, so do not drain it completely.
Is the NOCO Boost GB20 worth buying for a small car?
Absolutely, if you drive a 4.0L gas engine or smaller and you want the lightest possible jump starter for your backpack. The GB20 is the most portable option in the lineup and still includes the same UltraSafe spark-proof technology as the bigger models. The trade-off is no built-in flashlight and less power if you ever need to jump a friend’s larger vehicle.
How many jumps can a Noco Boost do on a single charge?
Most Noco Boost units can perform 20 to 30 jump starts on a full charge, depending on the engine size and how deeply the battery is drained. I have gotten about 25 jumps out of my GB40 before needing to recharge it. Cold weather reduces the number of jumps you get, so keep that in mind during winter months.
Do Noco Boost jump starters work in cold weather?
Yes, but lithium batteries lose some efficiency in freezing temperatures. The standard GB20 and GB40 still work down to about -4 degrees Fahrenheit, though you might get fewer jumps per charge. The GBX45 with its Boost X battery cells handles cold weather noticeably better, which is worth considering if you live in a northern climate.
My Final Verdict
After testing all three, the NOCO Boost GB20 is my top pick for anyone who genuinely wants to carry a jump starter in a backpack every day. It weighs barely over a pound, still delivers 500A of UltraSafe power for 4.0L gas engines, and costs less than the bigger models. The GB40 is the runner-up for drivers who need diesel capability, while the GBX45 is the right choice if you own a large truck and still want backpack portability.
If you drive a standard gas car and weight is your main concern, grab the GB20 and never look back. If you need the extra power for a diesel or a larger SUV, the GB40 gives you the best balance of capability and portability without overspending.
Winner: NOCO Boost GB20
- START DEAD BATTERIES — Instantly start dead batteries with 500 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
Buy this if you want the lightest possible backpack jump starter that still starts a 4.0L gas engine. The 500A peak power and UltraSafe clamps make it a no-brainer for daily carry.
Runner-Up: NOCO Boost GB40
- START DEAD BATTERIES — Instantly start dead batteries with 1000 amps of...
- ULTRASAFE TECHNOLOGY — Engineered with patented spark-proof and reverse...
Buy this if you drive a diesel or a larger gas SUV and still want a unit that fits in a backpack. The 1000A peak power covers 6.0L gas and 3.0L diesel engines with ease.
Third Place: 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...
Buy this if you own a large diesel truck or a big V8 gas engine and refuse to sacrifice backpack portability. The 1250A peak and cold-weather battery cells are worth the premium.