NOCO Boost GB40 Review: The Jump Starter I Actually Keep in My Car

Dead batteries don’t care how new your car is or how warm it is outside. Whether it’s a forgotten dome light or a dying alternator, battery failure is one of the most common—and frustrating—reasons people get stranded.

I’ve learned this the hard way.

That’s why I keep the NOCO Boost Plus GB40 in my car at all times. It’s not a gimmick or “just in case” gadget. I’ve actually used it multiple times—on my mom’s old Infiniti FX35, on a neighbor’s Civic, and even during a cold morning cold start on my own car.

What Is the NOCO Boost GB40?

The GB40 is a compact lithium-ion jump starter that fits in your glovebox but packs enough punch to jump-start most 12V vehicles without needing another car.

Quick Specs:

• 🔋 Peak Current: 1,000 Amps
• 🚗 Engine Support: Up to 6.0L gas / 3.0L diesel
• 🔦 Features: LED flashlight, USB power bank, reverse polarity protection
• 🧊 Temp Range: -4°F to 122°F
• 💵 Price: $100–$120 depending on current sales
• 🔗 See full details on Amazon

Real-World Testing

Unlike many reviews out there, this isn’t based on reading Amazon comments or watching YouTube videos. I own this thing—and I’ve used it.

Here’s what I’ve jump-started with it:

• A completely dead Infiniti FX35 with a battery that hadn’t been changed in years.
• A neighbor’s Honda Civic on a random weekday morning.
• A Toyota Tacoma that had been sitting for 3+ weeks.
• A Subaru Outback during a sub-freezing cold start.

In every case, the process was simple:

1. Clamp on (red to positive, black to negative)
2. Wait for the green light
3. Start the engine

That’s it. No sparks. No fumbling. Just results.

What’s in the Box?

• GB40 jump starter unit
• Heavy-duty clamps
• Micro USB charging cable
• 12V car charger
• Soft pouch
• Quick-start guide

Everything fits in a small bag that lives in my trunk with zero hassle.

What Makes It Stand Out?

Jump starters aren’t new. But here’s why the GB40 is my go-to:

✅ Compact but Powerful

Roughly the size of a paperback book, but delivers 1,000 peak amps—enough to start most sedans, crossovers, and small trucks.

✅ Foolproof Safety Features

Spark-proof clamps and reverse polarity protection mean you literally can’t screw it up. I’ve even touched the clamps together (don’t try that with cables).

✅ Manual Override for Completely Dead Batteries

If your battery is so flat it doesn’t register, the GB40 has a manual override mode. I used this on a car that had just 9V left—worked like a charm.

✅ Dual Use as a Power Bank

You can charge your phone or tablet in an emergency. It’s not a massive battery, but it’ll give you one full smartphone charge and still have enough juice for a jump or two.

Limitations (Because Nothing’s Perfect)

• It won’t jump start large diesel engines or heavy-duty trucks
• Manual override mode takes an extra step or two
• No USB-C (still uses Micro USB to recharge)
• Not ideal for commercial or repeated daily use—consider the GB70 or GB150 if that’s your situation

Why You Might Hesitate — and Why I Didn’t

It’s easy to assume you don’t need something like this—until you're stranded in a parking lot, on the side of the road, or in the cold with no one around.

You don’t need it... until you really need it. And then it becomes the most valuable thing in your car.

Final Verdict

The NOCO Boost GB40 is honestly one of the best purchases I’ve made for my car. It’s saved me, helped others, and delivered every time I’ve needed it.

It’s compact, easy to use, and gives you the one thing that jumper cables don’t: independence. You don’t need another car. You don’t need a mechanic. You just connect, press a button, and go.

🔗 Check it out on Amazon here →

It’s the kind of product you hope you’ll never have to use—but when you do, you’ll be damn glad it’s there.