NOCO Boost GB40: 1000A UltraSafe Jump Starter – 12V Lithium Battery Booster Pack, Portable Jump Box, Power Bank & Jumper Cables - for 6.0L Gas and 3.0L Diesel Engines

Overall, I have been very impressed with the NOCO Boost GB40 as an actual jump starter. When charged and ready to use, it has worked reliably for me multiple times over the years and has successfully jumped my vehicle without much trouble. The compact size and portability also make it much more convenient than dealing with traditional jumper cables. The biggest issue I have experienced is long-term battery retention during storage. I would fully charge the unit to 100% and keep it in my trunk specifically for rare emergency situations, but because those situations are thankfully uncommon, I would often discover that the internal battery had completely drained by the time I actually needed it months later. In practice, that means this works best for people who either: regularly maintain and recharge the unit, frequently use it, or own vehicles that commonly need jump starts. If you are expecting to charge it once and forget about it for extremely long periods, you may want to check the battery status more regularly than expected. I also occasionally tried to use it to help other stranded drivers, but the same issue sometimes came up where the unit had already self-discharged from sitting unused too long in the trunk. To be fair, I do not know how much of this is normal lithium battery behavior versus the device itself, especially considering temperature changes inside vehicles over long periods. But it is still something buyers should realistically know before relying on it as a long-term untouched emergency backup. Overall, I still think it is an excellent portable jump starter and a very useful tool when properly maintained and kept charged. I just recommend periodically checking and topping it off instead of assuming it will stay at full charge indefinitely in storage.

OK, I bought this in July 2024. It’s March 2026 and I used it for the first time. There was at least a six month period where I did not charge it and I was a little concerned whether it was going to hold the charge. I charged it two months ago, it still has full charge, it was super simple to use and quick to jump a vehicle with a dead battery. The only thing is the instruction booklet has tiny writing so read it ahead of time and maybe write yourself down some instructions and laminate them so the paper lasts in the car :-) Two people in the parking lot took pictures of this so they could get it for their cars. Highly recommended.

I’ve been using the NOCO Boost GB40 1000A UltraSafe Jump Starter for a while now, and it’s one of those things you’re really glad to have when you need it. It’s compact but surprisingly powerful—I was able to jump a dead battery quickly without needing another vehicle. I love how straightforward and safe it feels to use, especially with the spark-proof connections and reverse polarity protection, which takes the stress out of it . It’s also nice that it doubles as a portable charger and has a built-in light for emergencies. Overall, it’s a reliable, no-fuss tool that gives real peace of mind to keep in the car

Really solid emergency tool to keep in the car. It’s small enough to stash in the glove box but powerful enough to actually start a dead battery fast. Super easy to use—just plug it in and the safety features basically guide you so you can’t mess it up. It feels well-built and not cheap, and I like that it doubles as a phone charger and has a flashlight too. Definitely one of those things you hope you never need, but you’re really glad you have when you do.

Like others have said, the lack of any instructions and the lack of a wall charger makes it less than a 5 star product. I was getting ready to give it a 1 star review because it stopped working. I was having battery trouble with my wife's car and used it twice to start her car. It worked wonderfully and was much easier than using cables and my car. On a third time of using it I couldn't get the "ready" light to stay on and it didn't charge at all. The unit was fully charged, it just didn't work! Cables to the rescue! Again, needed to use it and couldn't get the "ready" light to stay on. THEN... I watched the video on doing a safety override, needed when the dead battery is completely dead. I used this feature and it worked perfectly to start the car. Well done me for checking everything available before sending it back! :) Although having that in a manual would have been nice.

A great tool and it holds a charge for a long time. Good size and easy to use, I’d recommend it to anyone. Also, the jaws on the leads are very sturdy and better than the one o got off the snap on truck!

This review is for: NOCO Boost Plus, Model GB40 ============================ Short Version: I love this device and will likely never go without one again. It's a reliable and easy to use jump-starter, power bank and 7-position flashlight all-in-one, so what's not to like? I would recommend this NOCO device to anyone who owns a car. Consider it one-payment dead battery insurance with no wait, delays, or co-pay. ========================== • MY EXPERIENCE: My car developed a short in the door lock mechanism that drained the battery in less than 24 hours. Between the inept Ford dealership and the excellent local private automotive shop, It took 5 weeks and several visits to trace and repair the short. In the meantime I needed a reliable way to jump-start my car on a nearly daily basis. After searching Amazon, I purchased this jump starter based on the overwhelmingly positive reviews. And it has really served me well. It was used multiple times between shop visits and has been used multiple times since then. It has been reliable when needed, jump-starting cars with ease. The Li-Ion battery holds a charge for a very long time. After sitting on the shelf for over 6 months it still appeared to hold nearly a full charge. And then only took about an hour to top it up. I've carried jumper cables in my trunk my whole life, but when a jump is needed you can never be certain someone will come along who's willing and has the time to assist you. This powerful jump-starter eliminates that uncertainty. It's also very easy to use and makes a great present for friends and family - even those who aren't very mechanically inclined. • USEFUL LIFE & RECHARGE FREQUENCY - From NOCO, when answering a question here on Amazon: 'The Boost should last several years with regular use and proper storage. To help extend the life of the internal battery, use and recharge at least every couple of months.' - Not everyone will have a need to use this device as a power bank, so the battery won't get properly charged and discharged as described. In that case my suggestion is to use the NOCO every month or two to charge your cell phone. - From NOCO, in the Important Safety Warnings section of the instruction manual: 'To ensure maximum battery life, avoid charging your product for more than a week at a time, as overcharging may shorten battery life. Over time, an unused product will discharge and must be recharged before use. Disconnect the product from power sources when not in use.' • FEATURES: - Powered by a (non-replaceable) 12v 1000A Li-Ion battery. - Battery Connection Safety -- 'Safely connect to any 12-volt vehicle with our mistake-proof design featuring spark-proof technology and reverse polarity protection' - Has a Manual Override, which allows the unit to jump start a battery that is discharged below 2v. - Also serves as a USB connected Power Bank - Includes a 7-position torch light • CONNECTIONS: - 12v Out - The included battery clamps are to be connected here. This is a unique connector so you cannot connect the jumper cables stored in your trunk directly to this device. - USB In - The included cable, or any USB to micro USB charging cable can be plugged in here in order to charge the NOCO jump-starter battery. The power rating of the charger device will dictate how fast the NOCO will come to a full charge. - USB Out - Let's you use the NOCO as a Power Bank (5V, 2.1A), using a standard USB cable. • RECHARGING - Time needed to charge the NOCO - The following comes from the User Manual. Assuming a nearly or fully discharged NOCO GB40: Charger (source) Rating = Full Recharge Time. [.5A = 12h], [1A = 6h], [2A = 3h] • EASY TO USE: 1. Plug the clamps into the NOCO. 2. Connect the clamps to the car battery. 3. Press the NOCO power button to turn it on. 4. Start the car. 5. Press the NOCO power button to turn it off. 6. Disconnect the device from the car battery.

The NOCO Boost Plus GB40 is one of the best purchases I have ever made. Now, three more members of my family have one. I purchased one for my motorcycle since sometimes I don’t ride for a while due to travel or weather. This gives me peace of mind knowing I can start the motorcycle no matter what. I once had to use it when commuting from work because I didn’t notice I had left the flashlights on all day. Eventually, I ended up getting a GENIUS5, also from NOCO, to keep my battery charged. Since then, I haven’t used the GB40, but I still keep it in my pannier, charged just in case. I was so happy with the GB40 that I recommended it to a family member. They got it and, fortunately, didn’t need to use it. Then, on a recent trip to visit them, one of their cars had been parked for a couple of days with some lights turned on. The battery was completely dead, showing less than a Volt on a multimeter. Of course, the NOCO starter didn’t recognize the battery as it was too low. We used the boost mode and were able to start the car with no issues. My family was so happy with the result that they bought two more to have one in each car. What I like: It has safety checks to prevent sparks, shorts, and reverse polarity (this also detects the voltage on the battery, which means if the battery has very low charge, it will fail to start in the normal mode). The boost mode disables all safety checks and works similarly to using cables from one car to another. This is a bit risky and you don’t want to use it often, but when you need it, it’s a relief to have. The cables are short and seem of good quality. The crocodile clamps have a firm grip without damaging battery connectors. It’s not bulky; I keep mine in one of the motorcycle panniers and it doesn’t take up much space. I probably should have bought the GB20, which also has the boost mode but is cheaper, and for a motorcycle would be more than enough. However, I vaguely remember it was not available when I got mine. I don’t regret it, though, as the GB40 can start a motorcycle (even a car) several times before needing to be charged again. You can use it as a lamp or emergency light, and also as a power bank for your phone or any other small device. What I don’t like: Storing it in the provided bag works but feels a bit messy. Other models, such as the GB70, can accommodate the clamps on the starter, which seems much cleaner. There is a case you can buy, but that will consume space, which, in my case using a motorcycle, is not much of an option. The boost mode is not really a boost, just a safety-disabled mode. I don’t like when companies use misleading names just to have a selling point. About the specs: I have no way to verify the claimed specs in the description, such as the 1000 Amps of discharge, but from a user’s perspective, it works with cars and motorcycles with no issues, even with flat dead batteries. In conclusion, I think this is a must-have. Hopefully, you don’t need to use it, but like insurance, you’ll be really happy to have it if you ever find yourself in a situation where you need it.

​Propriétaire d'un Peugeot 5008, j'ai été confronté à une batterie un peu faible avec le mode "économie d'énergie" qui s'activait sans cesse. Le NOCO GB40 à réglé le problème en quelques secondes, seul bemol les cables sont assez courts . A voir au fils des ans sont efficacité déjà démarrer 3 véhicules sans rechargement ​Efficacité immédiate : Malgré le gabarit du véhicule et l'électronique embarquée très sensible de chez Peugeot, le booster lance le moteur instantanément sans aucun message d'erreur au tableau de bord. ​Petite précision : Sur le 5008, l'accès à la batterie peut être étroit. Les pinces NOCO sont fines mais très robustes, ce qui permet de bien mordre les cosses même quand l'espace est limité. ​Sérénité pour les vacances : Avec une voiture familiale souvent chargée avec les enfants, tomber en panne sur une aire d'autoroute est un cauchemar. Ce petit boîtier retire un gros stress. ​En résumé : Testé et approuvé C'est un outil de qualité semi-professionnelle qui rassure toute la famille. Je recommande à 100% . ​💡 Le petit conseil en plus pour votre 5008 : ​Sur certains modèles de 5008, la borne négative (—) de la batterie est difficile d'accès car elle est reculée sous le pare-brise. N'oubliez pas que vous pouvez brancher la pince noire du NOCO sur une masse métallique du châssis (un gros boulon non peint sur le bloc moteur par exemple) cela à même fonctionné en rajoutant une rallonge car ma masse négative etait trop éloigné 👍

Ottimo avviatore! Il NOCO GB40 è compatto ma tira fuori una potenza incredibile: avvia l’auto in pochi secondi. Sicurezza al top, non fa scintille e si collega senza paura. La batteria dura tantissimo e si ricarica via USB. Perfetto da tenere sempre in macchina!

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I’ve had this for a couple of years now so have had chance to use it now and again. It started my wife’s (1.4L petrol) engine immediately when the car battery went flat, and again the next day, without a recharge in between. I had less luck trying to start the 2L petrol on a Mazda I had SORNed for two years during the pandemic - but it turned out the battery on that was completely gone (along with the bodywork of the car, sadly). So it definitely works for jump starts but it’s not going to provide you with a miracle. I have also taken this battery on a few camping trips. Its solid, rugged design makes it much better suited to tent life than are those slim portable batteries designed for business trips. It also has a decent torch built-in, and you can never have too many of them when you’re camping. I’d estimate it can recharge a modern iPhone from almost dead to full approx three times along with occasional use as a torch - so it can supply a family for a night or two, provided the kids are round the campfire not hiding in the tents on their iPads. You probably wouldn’t want to use it heavily for camping, as like any battery it may degrade to the point where the primary car start function fails, but it’s a nice bonus. I’m pleased with this purchase. It’s a handy device to keep in the boot of your car at all times and has the bonus capability of providing battery power outdoors. Even if you have other cars around, it’s easier to use this than traditional jump leads: you don’t need to move two cars close enough for the jump leads to reach, or open two car bonnets.

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