Affiliate Disclosure: As an Amazon Associate, Automoblog earns from qualifying purchases, including the jump starters featured here. These commissions come to us at no additional cost to you.

NOCO GB40 vs. NOCO GB70: Quick Take

Portable jump starters like the Noco GB40 and NOCO GB70 provide the convenience of on-demand power when your battery inconveniently dies. You don’t have to mess around with jumper cables or wait for roadside assistance, making the GB40 or GB70 ideal for a winter emergency kit. Beyond jumping a vehicle battery, extra features make either unit a convenient tool for camping, hunting, and fishing or to have around the farm or shop.

• When it comes to everyday vehicles: It’s hard to top the 1,000-amp GB40 with its compact design, integrated flashlight, and reasonable $100 price tag. If your “daily driver” is a typical sedan, crossover, or smaller SUV, the GB40 is the only portable jump starter you need.

• When it comes to heavy-use vehicles: Although the GB40 can handle gas engines up to six liters, the 2,000-amp GB70 is more muscular and offers peace of mind if you really beat the tar out of your vehicle. The GB70 is designed for larger gasoline and diesel trucks that endure strenuous miles due to heavy use from towing or moving sizeable payloads. It retails for $200 on Amazon. 

I own a NOCO GB40 and a GB70 and have been happy with both, save for one minor quirk about the GB70. Below I will compare and contrast each unit a little further.

Battery & Vehicle Compatibility

The NOCO GB40 and GB70 will jump various lead-acid batteries, including wet cell, gel, maintenance-free, enhanced flooded, and absorbed glass mat (AGM) batteries. Both will jump almost any RV, marine, four-wheeler, snowmobile, or lawn mower battery. The main difference between the GB40 and GB70 in battery and vehicle compatibility is their overall capacity.

For example, the 1,000-amp GB40 will handle gas engines up to six liters and smaller diesel powertrains up to three liters. The 2,000-amp GB70, by contrast, will jump gasoline engines up to eight liters and diesel powertrains up to six liters in displacement, including late-model HD trucks from the Big Three. That’s not to say it’s impossible for a GB40 to jump a truck battery (like a half-ton truck) or that a GB70 is “too big” for a sedan battery, more that each unit has different parameters on the maximum it can handle.

Clamps & Cables: Observations & Differences

The GB40 and GB70 have what NOCO calls “precision clamps,” which refers to the clamp’s spark-proof, crocodile-jaw design. This allows the GB40 and GB70 to safely and effectively bite down on batteries and terminals of different sizes. One potential downside is the relatively short jumper cables on the GB40 and GB70, which is forgivable since they are portable units and can be placed nearly anywhere under the hood to reach the battery.

One key difference is how the GB40’s clamps and cables are detachable while the GB70’s are affixed. The detachable cables of the already compact GB40 make it easier to stow in the microfiber bag NOCO includes with every portable jump starter. However, the GB70’s attached cables mitigate power loss during a jump, ensuring the unit is well-suited for larger engines, especially diesel trucks.

The potential drawback is how the GB70’s cables and precision clamps face away from the flashlight. On the left side is the charging bank, while the flashlight is on the right side. The cables and clamps trail back and away from the flashlight during a jump and go in the direction of the charging bank. Ideally, the flashlight and the cables should point in the same direction so it’s easier to see the battery, especially at night.

Integrated Flashlight & Charging Bank

Integrated into the NOCO GB40 and GB70 is a flashlight with seven different modes, including an SOS beacon and emergency strobe. The constant-on modes have three different brightness settings, from higher to lower. Given its size, the GB70 has a brighter 400-lumen flashlight versus the GB40’s 100-lumen flashlight.

Meanwhile, the built-in charging banks of either unit can charge a range of personal devices like phones, tablets, and e-watches. The main difference is how the GB70 comes with an XGC extension cord with a 12V male and female adaptor. Unlike the GB40, the GB70 can power other 12V devices, like a portable tire inflator (we sometimes use the GB70 to run our Slime inflator).

NOCO GB40 vs. NOCO GB70: Fail-Safe Designs

The best similarity between the GB40 and GB70 is the proprietary software platform within each unit called the Battery Management System, or BMS. As described by NOCO, the BMS is responsible for key safety features and creating a “mistake-proof” portable jump starter.

With the BMS, the GB40 and GB70 only output when the cables are correctly attached to a battery. For example, if you accidentally connect to the wrong terminal (reverse polarity), the units will not activate. Similarly, if the polarity is correct, but one of the clamps is loose, the BMS prevents them from delivering power.

With a proper connection, the white 12V LED light will illuminate. The units will make an audible click, indicating that jumping the battery is safe.

Rather than hitting everything they connect to at full blast, the GB40 and GB70 only deliver the juice required by the battery needing a jump. The units can tell the difference between a garden tractor battery and a truck battery and adjust power delivery accordingly.

NOCO GB40 vs. NOCO GB70 Verdict

• Affordable & Compact: The 1,000-amp NOCO GB40 is our pick as it accommodates a wide swath of everyday vehicles, both new and gently used. Slim and thin at under 2.5 lbs. with clamps and accessories, the GB40 is easy to stow. If you need a new, high-quality portable jump starter that won’t break the bank, the GB40 is a good pick for $100 on Amazon. 

• Robust & Powerful: As the bigger brother, the 2,000-amp NOCO GB70 provides more jumping power, a brighter flashlight, and a 12V power outlet. If you drive a bigger diesel truck, have a fleet of heavy-use vehicles, or want a portable jump starter with a little more muscle, the GB70 is a good value for $200.   

For additional insight on each unit and its features, take a look at our review of the NOCO GB40 and our review of the NOCO GB70. 

Carl Anthony is Managing Editor of Automoblog and a member of the Midwest Automotive Media Association and the Society of Automotive Historians. He serves on the board of directors for the Ally Jolie Baldwin Foundation, is a past president of Detroit Working Writers, and a loyal Detroit Lions fan.

Photos: Alex Hartman.

Original article: NOCO GB40 vs. NOCO GB70: The Difference Between These Portable Jump Starters & Which You Should Buy