Customer Ratings & Reviews

I recently purchased the Rexing 4000A Jump Starter and so far I’m very impressed with it. The unit feels solid and well made, not cheap or flimsy like some of the other jump starters I’ve seen. The LCD display is easy to read. One of the things I really like is that it’s more than just a jump starter. The 65W fast charging feature is great for charging phones, tablets, and even laptops while traveling. The built-in flashlight is also a nice bonus for emergencies or nighttime use. Heres what I think stands out about this charger most, is the fact that I can remove the jumper cables and store the unit in the case, if you’ve owned other car jumpers, then you know that the cables cant be removed. I tested it on my Jeep that had a dead battery and it started the car quickly without any issues. It gives peace of mind knowing I have this in the vehicle in case of an emergency, especially during winter or long trips. The carrying case keeps everything organized and compact, and the battery seems to hold a charge well. Overall, this is a very useful and reliable product that every driver should consider keeping in their vehicle. This is the BEST Jump Starter that I own. Thank You Rexing for putting out such a great product!

I bought this jump starter to keep in my car in case of emergencies, and I'm really glad I did. I drive an older model car and have had my battery die more often than I'd like, so having a portable car jumper is a must. I do pay for roadside assistance, but sometimes the tow service can take up to an hour or more, so it's nice to have the option to handle it myself. Out of the box it arrived charged to 81%, so I was able to test it right away without waiting around for a full charge. Build quality feels solid and durable. It's noticeably heavier than I expected for something this compact. The display is a nice and easy to read the battery level and status. The 65W USB-C charging is a great bonus feature. It charges up fast, and I've used it to top off my phone a couple of times when I was out and about. Having a USB-C in/out port plus the USB-A QC3.0 port means it doubles as a backup power bank, which makes it feel like less of a one-trick item sitting in my trunk. I was recently at a convention and someone nearby needed a jump. I was excited to try it out for the first time, so I offered to help and hooked up the cables, pressed the boost button, and their car started right up within minutes. It was so much easier than I expected, and it felt great to actually help someone out on the spot. It does mention that it supports vehicles up to 10L gas/diesel engines, trucks, boats. I only have a car so I can't personally speak to those use cases, but it's reassuring to know it has that kind of headroom. The multi-mode LED light (steady, strobe, SOS) is a nice added safety feature for nighttime emergencies too. Having this device in my car makes me feel a lot more confident and at ease. Highly recommend keeping one of these on hand.

Excellent quality jump starter. Very easy set up, easy to use and very versatile. Two cords come with the unit, USB-C to USB-C and USB-C to USB. The unit itself had one USB-C plug and two USB plug in’s. The flashlight alone is worth the purchase. The jumper comes with a very nice soft side case to contain the unit, jumpers and the cords. The size is larger than some of the other small options but much smaller than the old jumper boxes. This jumper does the job intended without question. This Rexing jumper lives up to the quality you would expect from a Rexing product.

I purchased this Rexing Jump Starter to boost my Kubota construction equipment and my Ford F250 diesel which has a battery drain problem. Rexing has three different models: the 2000, 3000, and 4000 amp versions. I went with the largest one because the diesel engines have high battery drain from the starter motors. The package arrived from Best Buy 2 days ahead of the expected delivery date which was great. Inside the box are the booster unit, a set of jumper cables, a USB C charger cable, and a USB A charger cable. There are two USB A plugs and one USB C plug on the unit for connecting your devices which is handy. The USB C plug also doubles as the charging port. My unit arrived with 73% charge on it and in less than an hour it charged to 93% charge with a 20 watt USB C charger block. The light is very bright and activates by holding down the power button and quick presses of the power button turns the light from steady to SOS and flash modes. This feature is very nice if you are stranded on the road at night. The display is awesome showing percent charge remaining, output watts, boost mode when activated for the jumper cables, and which ports are sending or receiving power. The unit itself and all the cables fit very nice in a zippered case which can be easily stored in the trunk of your car. The real test of a jump start booster is how well does it boost. As mentioned before I own several types of diesel equipment that are not frequently used. My Kubota excavator is five years old with the original group 24 battery. After a long winter of no-use, the battery would not crank the engine. I connected the Rexing Jump Start and it cranked right up! I took a photo of the booster connected to my excavator but could not upload the video which really shows it in action. I am sold on this product which is much easier to connect than driving my truck up to side of the equipment to boost it with jumper cables or trying to run a battery charger overnight while it charges. There is no electricity at my pole barn so trying to connect a battery charger would require me to get a portable generator to connect the charger to. This portable booster is way more convenient! My truck battery is holding a charge (for now) so I could not test the Jump Start on it, but I suspect it will work as well as it did with the Kubota equipment. Although this booster would be good as a backup USB charging battery and an emergency light, it really shines as a battery booster for your auto, lawn mower, or heavy equipment. As already mentioned, the booster worked great getting my Kubota excavator cranked with a dead battery. I highly recommend everyone keep one handy should you experience a dead battery.

This is a really high quality jump starter, Rexing is really trying to vie for title when it comes to measuring up to the leading brand. In terms of construction, this is a heavy-duty unit that feels and weighs substantial. 4000A is a huge battery and this is guaranteed to jump start the bigger motors that are out there. Alternatively, if you don't have a larger engine, this can power your electrics for a longer period of time since it's 4000A. The charging cables are also high quality and the gauge of the wire should definitely suffice. The nice thing is that the pair is terminated in a plug which allows for a direct connection without having to deal with a separate positive and negative plug. In terms of the ports, you have everything you need as well, with the various USB A and C ports to be able to charge whatever it is you have on hand. And at 65w, it's quick enough to charge your laptops as well. The carrying case is a nice tough to ensure that it's easily portable. The display is also easy to read.

Excellent jump starter. Feels and looks solid. Easy to read display. Even shows the watts being used along with battery percentage. Nice zippered case keeps everything in one place. Only negative I see is that it is bulky, but that doesn't bother me one bit.

When I received this product I was immediately impressed with the quality of both the product and the padded protective case. It had a 70% charge, so I plugged it into my Samsung USB C charger, and it took less than 1 hour to get to 100%. But how to test it? Car batteries were at full charge. However, my 1200CC jet ski which came out of storage 2 days before had a 40% charge on the battery. It would not even turn over. I attached the Rexing 4000 to it, let is sit for a minute, then tried to start. It cranked like the battery was at full charge and immediately started. Very impressive to say the least. It has a nice protective case, so I don't have to worry about damage from bouncing around. All in all, a nice product at a reasonable price! No sure if I will keep it in the car, or on the jet ski. Or, just move it back on forth when I launch. Nothing worse than being 2 miles offshore with a dead battery..

The Rexing 4000A jump starter is a reliable and powerful emergency tool. It easily handles dead batteries, even on larger vehicles, and the clamps feel solid and safe to use. The 65W USB‑C fast charging is a nice bonus for quickly powering phones or laptops. It holds a charge well and is compact enough to keep in the trunk without taking up much space. Most importantly, it gives real peace of mind—unexpected battery issues can happen anytime, even with a new battery installed. We recently suffered a thunderstorm that made several trees fall, one of them landed on the power lines, provoking 12 hours of no power, and the Rexing 4000 light us for several hours, good work Rexing. Overall: A dependable, well-built jump starter that’s worth having in every vehicle or home.

I grabbed the Rexing RJ4000 Jump Starter to keep in my trunk for road trips, and it's honestly a total lifesaver. Massive 24000mAh battery and 4000A peak power, it has no problem jumping basically any car or truck, and I love how rugged and weather resistant it feels. The best part for me is the LCD power draw display, which takes all the guesswork out by showing exactly how much juice is left and how much your devices are drawing as It also doubles as an amazing power bank with 65W fast charging,

I have had this product for a few weeks now and it has already saved me a AAA call and wait time. You hold the power button to turn on the leds and press again for different modes. It tells you when the terminals are connected wrong and shows battery remaining. Its fast to charge and has the ability to be used as a usb charger for phones, devices etc. It is a 4000 A so its on the bigger side, great for larger suvs. Turned on my 1991 land cruiser with the first crank. This is a picture of it next to a 1500A jumper.

Rexing doesn’t disappoint with this device. Comes with all the needed functionality for an unexpected emergency. From a device charger, flashlight ( flashing lights) to an automotive battery quick start. Comes with a heavy duty storage case. A must have in every vehicle. Nothing negative about this Rexing product.

Got this to keep in my truck because you never know when you’ll need it. I charged it up when I got it and have checked it a few times since. Battery has held up good. The screen is easy to read and I like being able to see exactly how much charge is left. The flashlight is handy too. Jump started my diesel truck with no problem. Definitely worth the peace of mind to have for an emergency.

A quality Jump Starter is an essential requirement for all vehicles. The new Rexing 4000A Jump Starter has several of the features that I like most in a modern Jump Starter. The 88.8 WH size means you can use it to jump start your car and also to charge your phone and laptop when you are away from home. I was able to charge a full size laptop from dead to fully charged and still had a charge .Another great feature is the 12” cables. A lot of the Jump Starters use cables so short the Jump Starter has to be sitting on the battery to hook up and even then it is sometimes difficult to arrange it so it can be securely clipped to the battery so you can start the vehicle. The Rexing Jump Starter also includes a durable zip up protective case that has a separate zip up section that holds the cables and clamps to keep things organized. This is a great addition to the Rexing product line and holds a charge well while in the trunk in case it is needed. Also the one button operation is so easy anyone can use it but also includes the Boost feature for jumping large engines or using the Jump Starter when it is partially depleted. The Jump Starter also recharges quickly with an input of up to 65W and has a large bright display that shows the accurate percentage of charge and input or output power. It also has the ability to supply power via 2 USB A connectors and one USB C connector. The same USB C connector is also used for recharging the Jump Starter. The Jump Starter also includes a bright light that has flashing modes for safety at night.

Very powerful jump starter. The Rexing 4000A is a powerhouse. I had the opportunity to use it on my lawn tractor twice now and it felt like the engine would jump out. I usually have a hard time getting it started even with a fresh battery but with the 4000A it started with no problems. I used it twice without charging it and it still has 90% charge. The carry case is good and protects it from damage and holds everything needed. And because it will also charge my phone, iPad and other gadgets the case has room for extra cables. I haven’t needed the light yet but it is bright and would be very useful if stuck on the side of the road at night. Overall this is something I’d definitely recommend. I’ve worked as an ASE certified mechanic for 22 years and had opportunity to use a few jump starters in my time and I like this one because of its simplicity, power and size. Bottom line, if you’ve ever thought of buying a jump starter you will be happy with this one.

This is a great product. It is nicer than the previous jump starters we have owned. It is very sturdy and comes in a nice, sturdy case along with 2 different charging cables to charge phones and other electronics. It also has a bright built in flashlight. The LCD screen is great for displaying battery status and charging information. Fortunately I have not had to use the jump starter yet. But I feel confident that this product will work effectively. Rexing makes quality products and this is another one of their outstanding and useful products. I definitely recommend this product!

I’m really impressed with the Rexing RJ4000. It’s compact, easy to store in the car, and gives me real peace of mind knowing I have a reliable jump starter on hand. I also love that it works as a power bank and flashlight, making it a super handy all-in-one emergency tool. This is my fourth Rexing product, and have had no complaints or issues.

This jump starter is great. First off the jump starting capabilities. Use the included cables to connect to a dead battery. If you put them on backwards it won't blow the charger, the battery, or the car, it will alert you that polarity is reversed and you can just reattach and be good. If the battery is very low you can hit the boost button and still get back on the road quickly. The capacity is good and capable of many jumps before needing a recharge. The built in light is diffused and perfect for lighting up under the hood. There is a bright strobe function that could really help get you attention if you are on the side of the road and need help. I never thought about this function but it can be real helpful if a simple jump isn't enough to get you back on the road. There is a charge function in case what you need is a phone call and your phone battery is dead. You can charge multiple other USB devices at the same time. This can be useful if you want to charge devices without having to have your car turned on your draining battery or your gas. I have used it to charge my phone, a laptop, and earbuds. I keep this in my car and feel prepared for anything and capable to help others if the need arises. I cannot recommend one of these enough and this model checks all the boxes. The other thing is it's from a reputable brand. I don't want to trust a no name brand on a tool as important as this and inside a hot car where cheap batteries can explode. Get one of these and feel safe knowing that you are prepared.

Love the portability of the design and easy to store in the car. Have no had a need to test this yet and hopefully won’t need to for a long while. It’s always a hassle asking strangers for a jump. It arrived 88% - I charged it. It sat for a few days and still read 100%. However, would be recommended to pull it out once a year to check the battery life and recharge to keep it ready. Used it to charge a portable usb device and nothing exploded - so far so good.

I own a few Rexing products. Mostly dashcams. Now that they have a big boy jumper pack I was all over it. I have another company’s jumper pack and they don’t come with a case to keep it in which annoys me. I love the fact that this comes with a nice case! Oh…. The jumper itself is great too! Haha The huge light on the front that also becomes a strobe was a great idea. I geeked out when it showed the wattage in which it was charging, so cool!

My new car is now 3 years old so I know the OEM battery will die soon. I’m not ready to replace it yet so I bought a jump starter battery to keep in the car just in case. I am currently using 4 Rexing dashcams so I am familiar with their products. Their dashcams are on the high end of the price spectrum. But they last so I am happy to pay more for products I can depend on to work when I needed it the most like getting in a car accident. The same philosophy applies when my battery died out in bad situations. This jump starter is not cheap. But you will get what you pay for. What surprise me the most when I received it is its enormous size and heft. I know it has plenty of juice to start my car when I needed it. Everything fit inside a hard shell case so that I can store in the back of the car without worry about damaging it. The LCD readout of the battery reserve in percentage is super easy to read. Overall I am happy with my purchase and confident that this jump starter will do its job when my car battery died out on me. Bonus, now I don’t have to pull out my jumper cables when people ask me to jump start their car. This is so awesome.