GOOLOO GT4000S 12V 4000A Peak Jump Starter with 100W Two-Way Fast Charging

I saw this reviewed on YouTube from a creator called "Project Farm." He does some of the best real world test reviews out there. He tested 14 jump starters, including the Gooloo. The Gooloo jump starter came in second place overall and it was just $99. The first place jump starter was $370. An almost 4 times price increase for just a little improvement over the Gooloo jump starter. It arrived well packaged and included a ton of accessories. The Gooloo lets you jump start your car (which was super simple and worked great). But, it also has a built in light with several illumination patterns. I has two USB A output ports for charging your devices. A USB C port for charging the the Gooloo internal battery. The same USB C port can also be used as an output to charge your own device. It charged my video light at an amazing 40 watts (see my photo below of it charging). It also has a DC out port at 15V. There is a female cigarette lighter for the DC out port. However, I think 15 volts is a little high form some devices meant to run at 12 volts. So use caution. There is also a male cigarette lighter with a male USB C plug so you can charge the Gooloo from a standard cigarette lighter socket. There is a USB A to USB C male cord and a double male USB C cord included. This is a very complete package. I charged the Gooloo to 100% and then did a test start on my 4Runner. My 4Runner has an older battery that I am too cheap to replace. I tried to start the car, but it just went, "click, click, click." So I hooked up the Gooloo jump starter and it fired right up. Not only did it start, it cranked the starter with authority. As Project Farm would say, Very Impressive! The size of the Gooloo is larger then most jump starters. But, that is because it has a massive battery inside which provides the excellent performance. But, it is not too big to be cumbersome. Everything fit nicely into the provided storage bag. The instructions were very clear and simple to understand. Overall, I am super impressed with the Gooloo jump starter.

The GOOLOO GT4000S Jump Starter absolutely blew me away. I honestly can’t believe something this small can start a vehicle with a completely dead battery — and not just once, but multiple times on a single charge. It’s compact, easy to use, and incredibly reliable. The clamps are sturdy, the display is clear, and the whole process takes seconds. This is one of those tools you buy hoping you’ll never need it, but when you do, you’re very glad you have it. Whether it’s for your own car, a second vehicle, or to help out a stranded neighbor, this jump starter is a must-have. Totally worth it!

Purchased this after seeing a very positive review on YouTube. Well after purchasing in oct of 2025 I charged the battery, then stored it in my truck. Well I never had to use it until sept of 2026. So I was hesitant it would work; powered on the unit to 100% battery. I expected that when we would attempt a jump the battery displayed percentage would drop to zero and not turn over the engine. I was wrong. The car fired up instantly and we lost 2% of battery with this jump. Overall very impressed. The cable length was perfect for the application. Just knowing that the unit can sit and hold a charge for that long is very reassuring it will be ready when you need it. One small issue is this unit is not rated for larger diesel engine jump starting so I had to get a different jump starter for my Superduty truck.

I purchased this Jump Pack on Jan 10, 2023. There is not a single vehicle that this thing cant make crank better than a brand new battery in the car. I have purchased many as gifts and have recommended it to everyone I know. Fast forward to September 2026 and i noticed that the jump pack is beginning to swell. This leads me to believe the battery inside is beginning to fail. With that said, i will simply purchase another one to replace my failing one because this thing is simply amazing. I do mechanic work as a side hustle and I do use this thing more than most would. It has paid for itself many times over. Do i wish the battery wasn't swelling? Absolutely. But I am not naive to the fact that batteries have a lifespan and jump packs take a beating by nature of their designed purpose.

For me, this is a 5-star product. I have used it to jump start two different SUVs (and one riding lawn mower). It works! Using this is much easier, safer, and more convenient than using jumper cables connected to another vehicle. It holds its charge very well, even in my truck that is often parked in the hot sun. After about 4 months in storage it dropped from 100% charge to 97% -- and that was plenty to jump start an SUV. Definitely recommend. Definitely would purchase again.

Saw on Project Farm. Used on a totally dead Vanagon battery, no dash light, Attached the charger, charger 'ready' light came on right away. The charger ran the engine starter at twice the normal speed; started right up! Amazing.

This jump starter is able to jump a car with a discharged battery - but unfortunately batteries nowadays fail with internal damage, including shorted cells. This is especially true in warmer climates - batteries acutely fail and the internal cells get shorted together. In this scenario the battery offers little or no start assistance - and this jump starter fails horribly. In contrast the Noco 4000’A can jump a dead battery in this state without issue. I couldn’t even jump a small Toyota Corolla with a badly failed battery using this starter! A good way to test the performance is to completely disconnect the battery - the jump starter should be able to start the engine with no battery. This essentially simulates an internally damaged battery that offers no start assistance. The Noco gbx155 can easily jump my 6.9L diesel with batteries disconnected! If you decide to test with disconnected batteries make sure you utilize an inline filter (rectifier) - which you can easily make yourself or purchase. The alternator has a dirty DC output (as seen on an oscilloscope). Fortunately the battery acts as a filter and cleans this up before it reaches your sensitive electronics (including the PCM). Without the battery or a filter the alternator output can damage these components. You can also test with an old completely dead battery if you have one laying around. That is the real test - can it start your car with a completely dead and internally damaged battery (measuring only a few volts or less)! This unit - along with many of the cheaper jump starters - cannot! The Noco GBX155 (4250A) does it easily. The rating of these cheaper devices is ridiculously over-stated - even a cheaper unit claiming 8000A couldn’t start my truck with a completely dead battery - yet the Noco 4250A did it easily - and multiple times back to back on the same charge! And the Noco is considerably more expensive - and heavier / physically larger (batteries making up most of this added weight). The amp output specified by these cheap units is not sustained - it’s the best case “peak / burst” output not sustainable long enough to even start my vehicle! Realistically these are capable of a sustained output measuring 20-30% of the advertised output (if your lucky!). Laws of physics applies and size matters when it comes to sustained output from the batteries (the “C” discharge rate and how long it can be sustained at a given rate). This is why the much bigger and heavier Noco can actually output what it claims while the much smaller and lighter cheaper jump starters cannot. The lithium batteries do not have the capacity. Hopefully this review helps others. If your battery is merely discharged (left your lights on all night) these lower cost starters will work fine. But if your battery fails badly - which is quite common today especially in hot climate - these low cost starters will leave you stranded. There is a reason why brands like Noco are way more expensive - consistent with commercial starters dealerships use to jump their vehicles! The 6000A Noco is over a thousand dollars - yet you can get a 10000A starter from some vendors for under $100! If it seems too good to be true - it probably is! That 10000A unit can realistically put out a sustained 2000A output if your lucky! If you decide to go the cheaper route, test it under worse case scenarios as described in my review -: doesn’t matter how cheap or expensive the unit is if it lets you down when you really need it! Visit a Ford dealership - they sell jump starters in their parts department. They sell the Noco - which is the same brand device they use to jump cars on their lot that have been sitting for a while m. And no, this isn’t meant to be a plug for Noco - I simply mention Noco because it’s the only portable and affordable one I tested so far that actually works and performs as advertised! Larger commercial units with real lead acid / AGM batteries also work but these are outside the price range for most people looking for a simple personal use device - and far too big and heavy to easily carry with you!

The best feature is its jump starting capability. Just clamp onto the battery, get the READY indication, get into the vehicle and start it up. Next best, it does supply a good variety of auxiliary power for 12 vdc items that would be run off vehicle accessory (cigarette lighter) plugs as well as USB chargeable devices. Finally I like the digital displays that show the percent capacity (0-100%) of the unit's battery pack and the watts of power it is delivering to accessories or receiving for its recharge. Both of these readouts show reasonable accuracy with respect to electrical test equipment I have. Only thing Gooloo could do better on this model would be provide display metrics for amp-hours and watt-hours of energy to help manage the battery pack energy more wisely during use. But it is after all just a simple consumer product. Most of my disappointment with the Gooloo GT4000S falls within a couple of areas. First, the metrics in its specifications mislead and confused me. The 4000 peak amps seems to be just plain mythical hype. Even the 500/800 amp for a 3/5-second starting amp rating is a bit far fetched. The jumper leads themselves are merely #8 gauge wire not truly rated to withstand such enormous starting current. And inside the GT4000S, its crucial protection relay is rated for only about a 10th of that starting current. For long, trouble-free service life, this device' operation is likely premised on quick starting success with ample assist from the vehicle's battery. Lots of harsh service could likely result in early failure or degraded battery longevity. A puzzling metric in the specs is the milliamp-hour rating of 28,600 with a mere 99.2 watt-hours of battery pack gross energy. I deduced that this enormous rating of milliamps was with respect to capability dealing with USB devices that would charge with nominal 3.7 vdc operating voltage. However, when using the GT4000S as a power station for 12 vdc devices, you wouldn't likely have enough capacity to supply those kind devices over an hour or two. This should be more truly portrayed by a 7,000 milliamp-hour rating with respect to the internal Li-ion pack's nominal 14.8 DC voltage rating, that being what your 12V devices are actually working with. Finally, the provisions the GT4000S has for recharging its internal battery are a mixed bag. They include just a couple of USB-C cables, but no AC outlet power supplies for them. With typical USB AC adapters many people already possess, you could expect to AC charge the GT4000S from nothing over 5-10 hours. If you have a 60/100 watt USB-C AC adapter, you can cut that time down to 1.0-1.5 hours. Or if you use the provided USB-C cable that plugs into a vehicle accessory receptacle, with the vehicle running you can accomplish a100% charge in an hour as well. However, I found that the red colored charge cable provided becomes surprisingly warm after just a few minutes. It is delivering a solid 100 watts of charging all the while. I suspect this might not be the preferred full charging method for the GT4000S, more just a short (20-30%) boost to get into play enough to start a vehicle. In summary, I was intending to purchase the GT4000S mainly as power station with more utility than just a 2-3X per year personal vehicle jump starter. But I needed to decipher their specs more clearly to see that I should spend $100 more on something like a Gooloo GTx 280. This model provides much more "true" battery capacity for succeeding well at all the power station functions as solely at jump starting. Time will tell whether "rationing" of the power station will prove too tedious for me to find the GT4000S as broadly useful as I had hoped.

The real deal authentic and original very good bought the first one and my friend took it then I bought the other for me. I charged 3 phone twice and used it to jump the car battery work perfect

تمت تجربتها لأكثر من مرة على سيارة صديق ، كانت ممتازة واشتغلت السيارة بدون مشاكل ولم تسحب من بطارية الباور سوى ٥% في كل إشتراك وأراه معدل نزول جيد.