Stanley J309 Portable Power Station Jump Starter 600 Peak Amp Battery Booster, 3.1A USB Ports, Battery Clamps

This item was exactly what I was expecting it to be, and after reading the owners manual, I charged this as recommend. This winter I had to use it to jump my car that was parked outside overnight with temperatures below zero. My car battery was completely dead, so I used this product to jump my car which has a V6 engine and a battery more than six years ago old. My car started right up and I was on my way in minutes. I am very happy with this purchase and I am glad I have this option available to me for any future issues of getting my car started in the cold weather.

Great product. Perfect for small car (4cyl and small 6cyl). I bought one for my mother. It payed for itself within 1.5 months. She had to use it 3 times because of a loose connection on the battery. My wife has used hers numerous times to keep her phone charged. It keeps a charge for a long time also. I pulled it out of the car after about two months and it was still showing in the green. It also has a reverse polarity indicator and on and off switch. Great for the mother. She just hooks it up, checks the indicator, turns it on, then starts the car(Nissan Sentra). A friend of mine even used it to start his truck quite a few times till he could get it to the shop (Ford F150; unknown engine size). Son uses the light to read at night. Almost didn't get it back. Great for small to mid size cars/trucks/vans. Unit is quite durable also. Unit is not heavy either. My 66 yr old mother uses it and has not problems and feels much better knowing she doesn't have to worry about a dead battery and being stranded.

Before I get into how the actual unit performs, I want to clarify that in order to charge this unit, you will need an additional power cord. The charging jack on the back of the unit is relatively small, so it may be difficult to get a cord in there. I had to cut a little bit of plastic covering off of my extension cable in order to charge the unit. Now, having said that, the jump starter is a pretty good product. It's heavy, but at the same time feels relatively cheap. I charged it fully, as the instructions specified, and it was left in the back of my car for a few weeks until it was used to jump an older model VW Jetta. It took a couple of tries, but the unit did as promised. It was used again a day or two later when the car refused to start once again. Overall, not a bad product, I just don't know how long it will really last.

I am not a mechanic only an engineering student but at my old student job we regularly jump started cars on campus (a few times a night). I've read either very good reviews or reviews where it just did not work. This thing works with my Toyota RAV4 but would I expect it to jump start a full size SUV or a large truck, well I haven't had the chance to try but I figure you would probably need something with higher current output. I've used it a few times when I was silly enough not to remember to make sure my lights were off and when my battery was starting to not hold charge like it used to (before I replaced it). Since there is one with 500A I am assuming if you have a car with higher current demands you should probably get that one or even higher. Another thing to point out is that sometimes if your battery is at that point where it is barely holding on, there's a good chance you need a real car that can sit there and rev up until you do get some current flowing. I've had a few jump starts where I had to rev the truck for 10 minutes. A simple jump start would not have worked especially if it was this jump starter and often times it would even die again when we took off the cables. Before you buy, you should check the specs on whatever you are planning on charging. There were a few times we had to jump start larger vehicles and we almost always had to push on the accelerator to give it more juice so I am assuming you would need something with a higher current output than this basic 300A.

Poor quality - not what I've come to expect from Stanley. Bought it to get my car going after the battery got run down from a light staying on a very long time. At first, it was totally useless because the car's battery was just too flat - it could not begin to jump-start the car, despite the booster being fully charged (on receipt, I plugged in for about 24h before trying to use it, as directed), though when connected, it did provide enough juice to wake the car up somewhat (big deal). Then I discovered that its internal from-wall-AC charger is safe to use to charge a second battery via the jumper clamps, so I used it as a charger for the car's battery (while disconnected from the car of course). Once the booster showed a full charge via its lights, I disconnected it from the car and set it aside, hooked the car back to its battery, and started it up under its own power. Just in case, I took the booster with me, which still read as fully charged at this point. When I got home, I brought it back in the house and plugged it in, as the instructions make it clear that it can be left plugged in indefinitely without harm. Everyone knows how car batteries are. Run one flat even once, or leave it sitting too long while even somewhat low, and it's trash. That said, I had no choice but to keep using it for a while until I could replace it. So, some time later, I used the booster again to try to straight-up jump-start the car, this time with the car's battery still having enough charge to run everything else except the starter (enough to click its relay, that's about it) - so it was just low, not flat. The booster just baaaaarely had enough juice to get the car going. I figure it should be good for a least one more start after that, especially since I was about to take a drive to the store, and run a couple other errands, so I took it with me, STILL showing a full charge. I came back out of the store after an hour or so, and again the car's battery had only enough charge to run everything in the car but the starter -- but I expected that, so out comes the booster. Nope, no good. Despite there clearly being at least some charge in the car's battery, and the booster showing an adequate charge, the two together were not enough to do more than give the engine half a turn. I had to get a real jump start from a friend. The irony of that trip? The very first thing did when I walked in the door was to head for the automotive department to look for a new car battery. No such luck though. Had to go to the local Autozone for a compatible one (due to the need for dual top-post and side-lug connections -- thanks GM! :-P ). While I was there, I had them check the charging system -- it tested good. When I returned home, I plugged the booster back in. It sat that way for perhaps a week, until I had to unplug and move it out of the way to do some routine vacuuming in that room. When I went to plug it back in half an hour later, It no longer showed a full charge - it self-discharged somewhat just sitting on the table, idle. Guess that explains why it didn't restart the car after I got done at the store. Um, guys, the whole point of a jump-starter/booster is to get the engine started when the car's battery is totally flat, to be able to do so at least a couple of times between recharges, and to hold a full charge for weeks on end. This one failed twice, barely worked once, and didn't hold a full charge after being unplugged for just half an hour. Bottom line: don't waste your money. Go to an auto parts store and talk to one of the associates there - get a brand they will stand behind. I'd get a refund on this unit if I could, but it took too long for the failure to become evident (I'm past the return window).

I just bought this as a gift for my dad and the same day I gave it to him, he got the opportunity to put it in use. It does exactly what it says and is so easy to use. Stanley is such a great name and the price was incredible! It has so many other features included in the jump starter pack beside just the need to jump your car. It has a flashlight, a USB plug and an extra AC adapter plug. Also a cell phone can be charged into it. Everyone with a car, new or used, should have an AMP JUMP STARTER. Not only does this product save time but it saves you the embarressment of having to search down some stranger and ask them if they can give you a jump.

I couldn't love this thing more if it handed me money. I don't drive my old car often, so it has a tendency to sit unused, and of course, the battery isn't a big fan of that, so when I do want to go somewhere, the battery is usually flat as a pancake. This jump starter is exactly what I needed. It's so much simpler than having to get someone to give me a jump - just connect the clamps, switch it to on, and fire up the engine. I wish I'd had this ages ago. It is something you should consider keeping in the car during winter months (or any time if you're having battery issues). It has a lovely LED light to help out if you're stuck in the dark, and you can even charge your phone with it. This little piece of genius should be in everyone's garage - or better yet, in your trunk, ready for your next problem. Thank you Stanley, I love you!

Seems to perform as advertised. But as stated in the manual, this will need to be recharged about every month or so or else the battery will go empty and get ruined. You should also note that this does not support trickle charging, so you will need to unplug it when it's done charging to avoid overcharging. This is kind of a hassle, but not that big of a deal. On the other hand, other brands seem to provide trickle charging support. I should also mention that the cables could be longer. These are something like 3-4' long. A lot of the negative reviews seem to indicate that this failed to successfully jump a car. Depending on your car, the amps needed to turn the starter over may vary. This should have no problem starting a car with just a low battery or smaller engines (say 4 cylinders), but if the battery is dead or the health of the battery is a problem, then you may fail to start your car. To see if this has enough amps, check on any auto parts store website to see the amp rating for replacement batteries for your vehicle. As an example, let's compare a I4 and V6 2007 Honda Accord. I'm using O'Reilly Auto for battery comparisons. I4: Cranking Amps range from 555 - 615. This jump starter should have no problems. V6: Cranking Amps range from 665 - 910. It is unlikely that this jump starter can start the car on a dead/dying battery. If you want to play it safe, make sure there's a safety margin between what the jump starter promises and what your battery is rated for. While it might seem somewhat expensive to step up to a higher rated jump starter (say 1000 or 1700 amps), you'll easily make back the difference the first time your car dies and no one is around to help.