The Difference Between These Portable Jump Starters & Which You Should Buy

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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 the battery inconveniently runs low. You don’t have to mess around with jumper cables or wait for roadside assistance to arrive, making the GB40 or GB70 ideal for a winter emergency kit. Beyond charging a vehicle battery, additional 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 beat the 1000-amp GB40 with its compact design, built-in flashlight, and reasonable $100 price tag. If your “daily driver” is a typical smaller sedan, crossover or SUV, the GB40 is the only portable jump starter you need.
  • When it comes to heavy vehicles: Although the GB40 can handle gasoline engines up to six liters, the 2000 amp GB70 is more powerful and offers peace of mind if you really strip the tar out of your vehicle. The GB70 is designed for larger gasoline and diesel trucks enduring grueling miles due to heavy towing or moving large payloads. It sells for $200 on Amazon.

I have a NOCO GB40 and a GB70 and I’m happy with both except for one small quirk about the GB70. Below I will compare and contrast each unit a bit more.

Battery and Vehicle Compatibility

The NOCO GB40 and GB70 will connect various lead-acid batteries, including wet cell, gel, maintenance free, enhanced flooded, and absorbed glass mat (AGM) batteries. Both will jumpstart just about 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 1000-amp GB40 will handle petrol engines up to six liters and smaller diesel powertrains up to three liters. The 2,000-amp GB70, by contrast, will power 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 that 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, just that each unit has different parameters about the maximum that you can handle.

NOCO GB40 sign in front of NOCO GB70.

Clamps and cables: observations and differences

The GB40 and GB70 have what NOCO calls “precision clamps,” which refers to the spark-proof alligator jaw design of the clamp. This allows the GB40 and GB70 to safely and effectively bite down batteries and terminals of different sizes. One potential drawback is the relatively short jumper cables on the GB40 and GB70, which is forgivable since they are portable units and can be placed almost 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 attached. The detachable cables of the already compact GB40 make it easy to store in the microfiber bag that NOCO includes with every jump starter. However, the GB70’s attached cables mitigate power loss during a jump, ensuring the unit is suitable for larger engines, especially diesel trucks.

The potential drawback is how the GB70’s precision cables and clamps are facing away from the flashlight. On the left side is the load bank, while the flashlight is on the right side. The cables and clamps back up and away from the lantern during a jump and towards the load bank. Ideally, the flashlight and wires should point in the same direction to make it easier to see the battery, especially at night.

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NOCO GB70
NOCO describes the GB70 as the “truck model” in their line of portable jump starters. Our only change would be to change the location of the charge bank and flashlight to make it easier to see the battery at night.

Integrated flashlight and charging bank

Built into the NOCO GB40 and GB70 is a flashlight with seven different modes, including an SOS beacon and an emergency strobe. Constant-on modes have three different brightness settings, from highest to lowest. Given its size, the GB70 has a brighter 400 lumen flashlight than the GB40’s 100 lumen flashlight.

Meanwhile, either unit’s built-in charging banks can charge a variety of personal devices like phones, tablets, and electronic watches. The main difference is that the GB70 comes with an XGC extension cable with a 12V male and female adapter. Unlike the GB40, the GB70 can power other 12V devices, such as a portable tire inflator (we sometimes use the GB70 to power our Slime inflator).

NOCO GB40 vs. NOCO GB70: fail-safe designs

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

With the BMS, the GB40 and GB70 only output when the cables are properly connected to a battery. For example, if it is accidentally connected 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 it is safe to jump the battery.

Instead of taking full advantage of everything they plug in, the GB40 and GB70 only give the juice required by the battery that needs a jump. The units can differentiate between a garden tractor battery and a truck battery and adjust power delivery accordingly.

Verdict of NOCO GB40 vs. NOCO GB70

  • Affordable and compact: The 1000-amp NOCO GB40 is our pick, as it fits a wide range of everyday vehicles, both new and used. Slim and lean at less than 2.5 lbs. With clamps and accessories, the GB40 is easy to store. If you need a new, high-quality jump starter that won’t break the bank, the GB40 is a good option for $100 on Amazon.
  • Robust and powerful: As a big brother, the 2000-amp NOCO GB70 provides more jumping power, a brighter flashlight, and a 12V outlet. If you drive a larger diesel truck, have a fleet of HGVs, or want a portable jump starter with a bit more power, the GB70 is good value for $200.

For additional information on each unit and their features, please see our NOCO GB40 review and our NOCO GB70 review.

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

Photos: Alex Hartman.

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