This is not the first one of these that I bought. I have both the 4000A and 3000A models that Autogen makes. They are both identical looking and the differences are internal where you can obviously guess the 4000A has a little larger capacity battery and can also provide 1000 more Amps if needed. A couple really nice features about these is that it has 2 Quick Charge 3.0 USB ports so it will charge your cell phone, or any other Quick Charge capable device in a fraction of the time that 2.5A or even the PowerIQ chargers. It also is able to RECEIVE charging from a Quick Charge 3.0 (QC 3.0) charger so it can charge a lot faster itself. It has a built-in smart charge feature which is not like a lot of other devices. Because this device has a lot of smart technology in it, when you plug in a USB cord to charge this device, it actually has a built-in battery monitor that checks the battery level and if it needs to be charged, it will then charge the battery. (which you will see the LED battery level indicators flashing when it's charging) Once the battery is completely charged, instead of the charger still supplying current to the battery it will turn off the charger. (Having the type of batteries that are in most newer devices constantly on a charger will actually lessen the life of your battery b/c every time the battery goes down even a little bit, and recharges, it decreases the remaining life of the battery almost as much as if you had run the battery down and recharged it. This is why if you read the owners manual on a lot of devices, they will tell you that once the battery is at 100% capacity it is best to disconnect it from the charger and not leave it on the charger) This same feature is also on the USB ports for charging other devices so if you plug in your phone or another device, once it's done charging, this power unit will turn off the power to the USB ports so it's not draining its battery, and it's not overcharging the battery of the device you are charging.Another nice feature this has is the built-in 12v power outlet (cigarette ligher power port) where a lot of the compact jumpboxes like this one have a 12v power outlet attachment that allows you to disconnect the 12v power outlet from the device. The problem NOT having it built-in is that for one, you can lose it. Also on pretty much every device I have seen where the 12v outlet isn't built-in, it uses the same connection that the jumper cables do, so it's an either/or situation. It's not a huge deal but if you have something like a work light or other 12v device you're trying to use and you need to jumpstart a car, UTV, ATV, or other vehicle, you can't have the work light until you're done jump starting the vehicle and swap out the jumper cables with the 12v outlet again. Like I said, not a huge deal, but murphy's law, it will be at night, so you need the work light, and without it you can't see the where the jumper cables/12v outlet adapter needs to plug in. Plus, all of the devices I have looked at where the 12v outlet is NOT built-in, the outlet can only handle between 6 - 8 Amps where this one supply 10 Amps of 12v power. This may not sound like a lot, but it's the difference of 200 - 400 watts of output, so if you have something you want to plug into it and has a 1200 watt output, this jump box can handle it, where another one that can only give 6 Amps of power would not.I have used my jump box quite a few times. Usually I'll see someone in a parking lot when I'm coming out of a store, and they have that international sign of distress (an open car hood) There have been a couple of times when it has been a diesel truck and because a diesel has a lot more compression, the starter for it takes a lot more power than a regular gasoline powered car. Normally, if you have a gasoline powered car, and you are needing to jump start a diesel, you will usually connect the jumper cables and let the gasoline powered car run for a few minutes (sometimes as much as 10 - 15 minutes) to let the diesel's battery charge up enough. But, with this, I hooked it up, he turned the key, and as soon as the engine was "Ready to start" (for those of you who are familiar with diesels, you know this is about 10 - 15 seconds if it's decently warm out) he cranked it over and this jump box gave enough power to start up the diesel like it had a brand new battery. Needless to say, I was really impressed. It wasn't a big rig diesel, but it also wasn't a small diesel. It was a 6.7 Litre, so it was decent sized and this had no problems cranking it over.I've gone months (probably around 5 - 6) between charging this, and I believe the highest amount of times I used it before charging it was around 8 or 9 times (mainly b/c I had to jump start a friend's car several days before he was able to find he had an intermittent electrical short that only sometimes drained his battery at night (turned out to be a worn wire that would shake enough every now and then and touch a piece of the frame and cause a short and drain the battery overnight, if you were wondering :-) ) Even using it that many times before charging it, it still had around 25% power left.All in all this is probably the best "small form" jump box that I have seen, which is why I bought the 2 (one 3000A, and one 4000A) Hopefully this review has given you a lot of good information, without being TOO long. I hope you are never in a situation where you need it, but if you are, I hope you took my word for it and bought this one or the 3000A model so the situation is more of an inconvenience than a crisis. :-DThe reason I've bought this jumpstarter is that had pretty much what I imagined the ideal emergency prep jumpstarter should have:* Clamps (obviously), detachable* Big enough to have a lot of power (around 20Ah, as biggest power banks have), but not as big as a small jerrycan, so it is still reasonably looks like and functions as a power bank.* At least two USB charge ports, preferably at least one being high amp (to charge tablets in a reasonable time)* Flashlight* Have enough amps to jumpstart at least biggest pickup trucks or small vansI was hoping the pictures do justice, and they do! It isn't cheaply made, well worth the money. Sides are rubberized (not simply plastic). Everything fits together well, looks great! Even colors are great! And I was pleasantly surprised, it comes with a carrying case which is also very well made! Good quality, well organized, with a little bit of extra space. Everything it comes with (clamps, instructions, charger) fits inside. The case is the one you would normally be happy to buy separately, but with this jump starter, it is included, and it fits well! If you want to have a jump starter with it all as a single purchase, maybe as a gift, totally buy this one!Also, it has cigarette lighter port, that's actually great! I can imagine there might be situation where this is useful.Instructions are four pages on a moisture-resistant paper, which is the best. Not a multi page manual for something so simple. Compact and clear, and has everything you need.Things that could be better (but I would buy this one regardless):* USB-C in and out, in addition to micro-USB in (I'd keep micro-USB around until~2025)* Long pressing the button turns flashlight on AND off (today you need to short press twice to skip through strobe and sos modes)Note: I haven't used it extensively, and honestly did not use it to jumpstart my car yet. But all the reviews I've seen looked good in this aspect. But if anything comes up in the future, I'll update the review.I'm going to buy another one within a year, in a different color scheme (4500 comes in green and metallic, I've bought the green one) - because two is one and one is none! Gonna give another one to my parents.Bought the unit in July. Made sure it was fully charged and placed it in the trunk. Car battery died yesterday. I used the unit and it easily started the car.This thing will actually turn over my 6.0L Powerstroke diesel. It will only do it once before needing a recharge. Still, it's pretty amazing that it will charge the truck battery enough to run the glow plugs, prime the injection system and turn the motor over.I bought this starter power bank because I am always working on other people's vehicles and equipment; as well as finding people in parking lots with battery issues and not like jump starting others with my vehicle battery. I also use this power bank out camping and fishing to charge my cell phone and charge my daughter's tablet. I have lost count of all the things I have used this starter power bank for, but I can tell you it has always done the job very well. I have used it on a few vehicles with battery issues so bad that after I get the vehicle running with my Autogen the vehicle will not stay running after removing the power bank. I very highly recommend the Autogen Portable Starter Power Bank to anyone who is always needing a great source of power for starting larger engines or just to be able to start many engines between charges. I very much depend on mine a lot and hope too never be without it.I’ve only used it once so far. It jumped a strangers vehicle that was broken down. It was a larger V6 in a truck. He had to crank it 3-4 times before it started. But the motor turned quickly indicating the jump pack was providing a strong jump. After this event the battery indicator lost 1 bar.I would have preferred a USB-C charging port to charge up the pack. This uses an older mini (or micro maybe?) USB style.