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.

I’ve been very satisfied with this jump starter. It has a compact design that makes it easy to store in the vehicle, while still being powerful and reliable when needed. It has already come in handy twice when my battery was dead. Overall, it feels well-built and dependable.

This booster is one of those products you hope you never need, but you’ll be so glad you have when you do. It’s compact enough to keep in the trunk or back seat without taking up much space, yet powerful enough to quickly jump start a dead battery with no hassle. I love how easy it is to use, even for someone who isn’t very car-savvy. The instructions are simple, the clamps feel sturdy, and the safety features give extra confidence when connecting it since I know I won't damage my car or harm myself. It saved me from having to wait for roadside assistance which is AMAZING! Overall, this little jump starter is absolutely worth it. Reliable, convenient, and a real lifesaver when you need it most.

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.

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

this is so quick to jump a battery, charges from dashboard, stays charged a long time. an excellent piece of equipment thats saved me many times when the lights were left on etc, and ive saved a lot of folks from drained batteries who were in a jam from calling AAA or abandoning their rig. very happy with many extra design features as well.

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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.

Très bien, testé sur un Scénic 3 1.6L diesel batterie à plat ( 7V) , la voiture a démarrée sans problème et sans le bouton booster . Le produit est bien protégé et semble robuste , compact dans son étui livré avec les pinces et le câble USB C . il peut être aussi utilisé comme chargeur grâce aux sorties USB. Le produit existe en plusieurs intensités , A choisir en fonction du type de véhicule

يؤدي عمله بشكل جيد

bra produkt, räddade, inte bara mig, några gånger i vintras.