Which NOCO Boost to Buy, and Will It Jump a Tesla?

For most cars, buy the NOCO Boost GB40. It lists at $99.95 on NOCO’s store and is rated for gas engines up to 6.0 liters and diesels up to 3.0 liters. TechGearLab, which tested 13 jump starters, named it its best compact model and says it easily starts small to mid-size cars and SUVs. The other picks follow engine size:

• Small car, gas engine up to 4.0 liters: the GB20, $79.95; NOCO lists it as not recommended for diesels.
• Most cars and small SUVs, gas up to 6.0 liters: the GB40, $99.95.
• Bigger V8s and diesels, gas up to 8.0 liters, diesel up to 6.0: the GB70, $199.95.
• The largest engines here, gas up to 10 liters, diesel up to 8.0: the GBX155, $369.95.

All four are sold by Amazon.com, and the prices above are NOCO’s own list prices on November 6, 2026.

Before you buy one for a Tesla, read the Tesla section below. NOCO’s GB40 user guide says the product is “only compatible with 12-volt lead-acid batteries,” and NOCO’s compare page rates every Boost in this guide for 12V lead-acid batteries. A Model 3 or Model Y built in Fremont after approximately December 2021, or in Shanghai after approximately October 2021, has a lithium-ion low-voltage battery instead.

The Boost and Boost X models by engine size

NOCO rates each Boost by the largest engine it can start, and that rating is the number to shop by. Find your engine size in your owner’s manual, then pick the cheapest model whose rating covers it, or one size up if you drive a big pickup or SUV or want headroom for hard starts.

NOCO lists the recharge times for the GB models at a 2-amp input and for the GBX models at a 10-watt input, and it flags a separate fast-charge input on some models without giving a time for it. TechGearLab’s specification table lists shorter times for the bigger packs: 3 hours for both the GB40 and the GB70, and 2.6 hours for the GBX155, which it says “charges quickly via its 60-watt USB-C port.”

The GBX models are NOCO’s Boost X line, and they add a USB-C output port that the GB models on this list lack. Each of the three smaller GBX models sits between two GB models on engine rating: the GBX45, for example, covers gas engines up to 6.5 liters and diesels up to 4.0 liters for $25 more than the GB40. NOCO also sells the AX65, a Boost with a built-in air compressor, and larger Boost MAX models; this guide does not cover them.

Best for most cars: NOCO Boost GB40

The GB40 is NOCO’s 1,000-amp Boost Plus, rated for gas engines up to 6.0 liters and diesels up to 3.0 liters, with a USB-A port for charging a phone and an IP65 rating with its ports closed. One TechGearLab tester said it “has proven to be able to start every vehicle” they tried it on, and in TechGearLab’s tests it “easily jump-started a 4-liter V-6 gas engine with a completely dead battery three times in quick succession.” TechGearLab gave it an overall score of 64.

Its weak spot is capacity. TechGearLab measured its battery at 15.57 watt-hours (Wh) against NOCO’s claimed 24 Wh, and warned that it “might not be able to jump larger pickups or big SUVs.” If you drive a big pickup or SUV, size up to a model rated with room to spare for your engine.

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Small cars on a budget: NOCO Boost GB20

The GB20 is the 500-amp Boost Sport, rated for gas engines up to 4.0 liters, and NOCO lists diesel engines as “Not Recommended.” It costs $20 less than the GB40 and has the same 3-hour listed recharge time, so it fits a compact car that never needs more. If anyone in the house drives something bigger, the GB40 is the safer gift.

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Bigger V8s and diesels: NOCO Boost GB70

The GB70 is the 2,000-amp Boost HD, rated for gas engines up to 8.0 liters and diesels up to 6.0 liters, with a 400-lumen flashlight. TechGearLab gave it an overall score of 71 and said it offers the GBX155’s “same rugged design in a smaller, less expensive package.” If your engine is between 6.0 and 7.0 liters gas, the $149.95 GB50, rated to 7.0 liters gas and 4.5 liters diesel, is the cheaper step up.

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The largest engines: NOCO Boost X GBX155

The GBX155 is the 4,250-amp top of the Boost X line, rated for gas engines up to 10 liters and diesels up to 8.0 liters. It had the highest overall score, 86, of the 13 jump starters TechGearLab tested, which called it the top choice “for those who need to jump start larger engines.” TechGearLab also found it “big and heavy,” so it suits a truck or a workshop more than a small car.

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How to jump start a car with a NOCO Boost

These steps come from NOCO’s GB40 user guide; check the guide for your own model. The guide says the pack “comes partially charged out of the box and needs to be fully charged prior to use,” so charge it from its USB port before it goes in the car. For the usual negative-ground car:

1. Read your car’s owner’s manual and confirm the battery is a 12-volt lead-acid one; NOCO says to verify that before connecting.
2. Plug the battery clamps into the Boost’s 12V OUT port.
3. Connect the red clamp to the positive (+) battery terminal, then the black clamp to the negative (-) terminal or the vehicle chassis.
4. Turn off the car’s headlights, radio and air conditioning, then press the Boost’s power button. If the clamps are on correctly, the white Boost light comes on; if they are reversed, a red error light comes on instead, and swapping the clamps clears it.
5. Try starting the car. NOCO says “most vehicles will immediately start,” but some need the Boost connected for up to 30 seconds first; if it does not start, wait 20 to 30 seconds and try again.
6. Once the engine runs, disconnect the clamps in reverse order and put the Boost away.

Do not keep cranking. The GB40 guide says not to attempt “more than five (5) consecutive jump starts within a fifteen (15) minute period,” and to let the Boost rest for 15 minutes before trying again. The same guide says to wear eye protection, not to wear metal such as watches or jewelry while working on a battery, to work in a well-ventilated area, and never to jump start a damaged or frozen battery.

When the Boost won’t turn on: Manual Override

A NOCO Boost will not send power to a battery it cannot detect. NOCO says the Boost is “designed to jump start 12-volt lead-acid batteries down to 2-volts,” and that if the battery is below 2 volts, the Boost light stays off, “an indication that Boost can not detect a battery.” TechGearLab describes the same thing across brands: many jump starters “won’t automatically attempt to jump-start a vehicle with a completely dead or nearly dead battery.”

The fix is Manual Override, which NOCO’s GB40 guide describes as “only for use when a battery is too low to be detected” and as a mode “for 12-volt lead-acid batteries only.” Never use it on a lithium-ion battery, such as the low-voltage battery in a newer Model 3 or Model Y. NOCO’s steps:

1. First remove all loads and try again; NOCO’s troubleshooting table lists that before Manual Override.
2. Check that the red clamp is on the positive terminal and the black clamp on the negative one.
3. Press and hold the Manual Override button, “the red exclamation point icon inside a red circle, for three seconds.”
4. The white Boost light flashes on and off when the Boost is ready to jump start.
5. When you are done, power off the Boost before you take the clamps off.

Use it with extreme care. NOCO warns that “both the spark proof and reverse polarity protection features are disabled in Manual Override mode.” The GB40 guide adds that the clamps must not touch each other, that the mode uses very high current (up to 1,000 amps on the GB40), that improper use “may result in injury or death and will void your warranty,” and that if you are unsure about the mode, you should not attempt it and should seek professional help.

Will a NOCO Boost jump a Tesla?

This section covers the Model 3 and Model Y, whose owner’s manuals are the sources here; if you drive a Model S, Model X or Cybertruck, check its own manual. The answer depends on which low-voltage battery the car has. On a Tesla, the job is to wake the car: Tesla’s steps are to open the hood using its procedure for a car with no power, connect the supply, turn it on and touch the touchscreen, with a note that “it may take several minutes for the touchscreen to wake up.” NOCO’s steps above are written for starting an engine and do not cover how long to hold power while a Tesla wakes.

Tesla’s manuals for earlier Model 3 and Model Y cars say vehicles built in Fremont before approximately December 2021, and in Shanghai before approximately October 2021, have a lead-acid low-voltage battery, and later cars have a lithium-ion one. To check yours, Tesla says to touch Controls > Software > Additional Vehicle Information. Do that before you need a jump, because the check needs a working touchscreen. The Tesla 12V battery guide explains how to tell which battery your car has and what a replacement costs.

Lead-acid Model 3 and Model Y. These match the battery a Boost is rated for: a 12-volt lead-acid one. Tesla’s lead-acid steps have you connect the supply’s red cable to the battery’s positive terminal and its black cable to the negative terminal, and warn not to let the positive cable touch other metal parts, “such as the battery tie-down bracket.”

Lithium-ion Model 3 and Model Y. Here NOCO’s own instructions say no. Its GB40 user guide says the product “is only compatible with 12-volt lead-acid batteries only” and that “jump starting other battery chemistries may result in injury, death or property damage.” The guide also says to contact the battery maker first and not to jump start a battery “if you are unsure of the battery’s specific chemistry or voltage.” Tesla’s current US manuals cover only the lithium-ion battery; their instructions “assume you are using an external low voltage power supply (such as a portable jump starter)” and do not name a battery chemistry for that supply. This guide’s advice: do not use a NOCO Boost on these cars, and ask Tesla which supply to use.

Two cautions from Tesla apply either way. Its Model 3 and Model Y manuals both say the car “cannot be used to jump start another vehicle,” and that connecting cables to the wrong jump post or touching the leads together can damage it. If the screen is still dark several minutes after power is connected, the black or frozen screen guide covers the other causes.

What “lithium” means on the box

Amazon lists each Boost in this guide as a “Lithium Battery Booster” or a “Lithium Jump Starter.” That describes the battery inside the Boost: NOCO calls the GB40 “a portable lithium-ion battery jump starter.” It does not mean the Boost can jump a lithium car battery; every model in this guide is rated to jump start 12V lead-acid batteries.

Before you wrap one

Charge it first and keep it topped up. NOCO’s GB40 guide says an unused Boost “will discharge and must be recharged before use,” and that it charges only between 0°C and 40°C (32°F to 104°F), so recharge it indoors in winter. The same guide says the device “is intended to be stored indoors when not in use,” which sits awkwardly with keeping it in a car; it rates the GB40 to operate between -20°C and 50°C (-4°F to 122°F). TechGearLab warns that harder starts could be too much for the GB40 if you do not recharge it “once or twice each year.” Write the engine size of the car it is for on the gift tag, so the person you give it to knows it covers their engine.

NOCO Boost questions

Which NOCO Boost do you need for your car?

Match the model to your engine size: the GB20 covers gas engines up to 4.0 liters, the GB40 up to 6.0 liters, the GB70 up to 8.0 liters and the GBX155 up to 10 liters. For most cars and small SUVs, the $99.95 GB40 is enough.

What is the difference between the GB40 and the GB50?

Engine coverage and price. The GB50 is rated for gas engines up to 7.0 liters and diesels up to 4.5 liters at $149.95, against 6.0 and 3.0 liters for the $99.95 GB40. NOCO also lists a longer recharge time for the GB50 at the same 2-amp input, 4.5 hours against 3.

Why won’t a NOCO Boost turn on when it is connected?

The battery may be below 2 volts, which the Boost cannot detect, so its Boost light stays off. NOCO’s Manual Override, held for three seconds, forces the jump start on for a 12-volt lead-acid battery only, and it disables the spark-proof and reverse-polarity protections.

Can a NOCO Boost jump start a Tesla?

Only a Tesla with a lead-acid low-voltage battery. Per Tesla’s Model 3 and Model Y manuals, that means a car built in Fremont before approximately December 2021 or in Shanghai before approximately October 2021. NOCO’s GB40 guide says the product is only compatible with 12-volt lead-acid batteries, which rules out the lithium-ion battery in later cars. For other Tesla models, check the car’s own manual.

Is the GBX155 worth it over the GB70?

Mainly for gas engines over 9.0 liters or diesels over 7.0 liters, where it is the only model here rated high enough; between those and the GB70’s limits, the $249.95 GBX75 or $299.95 GB150 covers more for less. It costs $170 more than the GB70, and TechGearLab found it “big and heavy,” though it scored it highest of the 13 jump starters it tested.