KeenPower 6000A Super Capacitor Battery-Less Portable Jump Starter for 12V Car, Built-in 6 * 3000F Supercapacitor, No Pre-Charging Need, Extremely Safe, Always Ready Jump Start All 12V Car

My 2007 Tahoe has an electrical leak. I just can't seem to find it, so at the most inconvenient times I have a low or dead battery.I charged this device with the usb only once when I first got it. Since then, I must have used it forty or fifty times and it worked every time. It draws whatever energy is still available in the battery (about 15 to 30 seconds) and stores it in a capacitor. Then it's ready to go, and for me, it worked every time! And, once your car starts, the capacitor is automatically recharged to 100% for next time.I know it's more expensive than a conventional battery charger, and it doesn't have some of the extra features like a light, but you are not going to be stranded because you forgot to recharge it.It is smaller and lighter than the big jump starters, but bigger than the small usb types, but honestly, the small ones, even the ones advertising a lot of amps, have never been reliable for me. That's why I took a chance on this, and I am glad I did.

I love this device! Even cables are less then cigarette in diameter but has no problem to start my 5L DIESEL truck loader easily.I use it frequently. I don't buy the loan mover battery anymore! I am charging it from the phone USB charger, takes 10 minutes max to just bring it back to 100% after being in storage for for a month...After starting the loader or mover or car it still have about 90%-95% of juice, planty for more attempts if needed (if car has some issues). After starting, I just keep it connected for a half minute till it shows 100%. Very good device!

This 6000A Super Capacitor Battery-Less Portable Jump Starter for 12V Car, Built-in 6 * 3000F Supercapacitor, No Pre-Charging Need, Extremely Safe, Always Ready Jump Start All 12V Car.Would struggle to jump start my daughter's battery which was only a year old but unused for almost 3 months & her car is from 2020 with low millage ( it a small car)....I first fully charged it to 100%, it arrived at 28%. VERY BAD box to jump start vehicles EVEN pretty small ones. ABSOLUTELY NOT POWERFUL AS IT CLAIMS TO BE. DEFINITELY NOT !NOT RECOMMENDED AT AL EVEN IF YOU GOT IT WITH THE 100$ DISCOUNT, WHICH IS WHAT I NEED. I will not spend even $100 on this . THEY ALL MUST BE DEFECTIVE one way or another. This will absolutely NOT last long NOT EVEN close!. :-((

I was so excited to use this after I received it, and it took a while to actually need it but when I finally did it was the coolest experience. I had a dead GMC Savanna work truck that had been double parked all day with the flashers on. There was nothing left when I got to it and barely had interior lights. No turning over at all. The Jump starter charged itself off the dead vehicle battery and when it had enough power, I initiated the jump feature, and the vehicle started like it had a fresh new battery in it with no hesitation. I have used it several times since and it worked flawless each time. It is smaller than I expected and doesn't feel super heavy duty but who cares if it does the job. I would say it takes between 2 minutes and 5 minutes depending on the state of charge left in the unit. I thought the capacitors would lose the charge, but it seems pretty stable when not used. Wouldn't matter though because it will charge right up off the failing battery. I had to use it again tonight to start my Dodge Durango which was run dead at a trunk or treat using the radio and interior lights for hours. It measured 10.3V when I attached the jump starter, and the battery pack took roughly three minutes to go from 18% to 100%. The previously "click only" state of charge instantly changed when the super capacitors threw power back, and it turned over the Hemi like there was never an issue. I am sold and am super glad I finally broke down and made the investment!

Fantastic, only desire is a longer countdown until it discharges. I haven't found something it couldn't start. Anything from cars, trucks, to my old dump truck, and even my heavy equipment and tractors. If the countdown until it discharges was longer, I'd be completely happy. Because of that, I tend to hit the button and have to hurry into the cab to start the vehicle. Definitely easier with two people, but that's never the case on a farm. I'd recommend this to anyone. I'd love to see a 24v model or one that could do both 12&24v!!!

I've been having trouble with several of my cars maintaining the batteries. My 1998 Silverado was left at my summer home and the battery would get so low that it would set off the car alarm. I charged the KeenPower off the dead battery and jumped the truck which started Immediately. I ran the truck for a few minutes, shut it off and tried to restart it without any luck. I recharged the KeenPower off the dead battery in three minutes and started the truck again. The truck battery can't keep a charge so I'll have to replace it.I also have a boat with twin crusader 200s that I haven't used since August on a mooring. Both starter batteries were dead and couldn't even run the bilge pumps. I turned over the first engine with the KeenPower but couldn't start it in the 25 seconds of discharge. I recharged it off the boat battery and started it on the second attempt. I recharged it again and started the second motor after two attempts.I really don't care what the critics and nay Sayers think about the KeenPower. I've never had a piece of equipment do what this thing did to my truck and my boat. No one in the boat yard could believe I could start the engines without having the boat towed to the dock.And by the way I also charge my cell phone to 80% capacity recharged the KeenPower and then charged the phone up to 100%.