Idk what's more impressive: How long this thing has lasted me without any degradation in quality, how much power this thing has or how quickly it jump starts a car.I've never seen another car charge a car battery enough to start the engine as quickly as this backup battery does.I got this in 2019 because I traveled a lot for work to charge my laptop. When I was no longer with that company, I didn't have much use for it so it sat on a shelf or in a box in the garage.I needed a jump one day and remembered this had jumper cables & pulled it out and shockingly it still had 2 bars of charge and started my car immediately.Ever since that day (2-3 years ago) I've always kept it in my car, charging it once in a while (but not often).I lent it to a neighbor who was having battery issues and he used it for about a week and returned it with ½ a charge (I know he didn't charge it because I had the charging cable).Recently, BOTH of my cars batteries died and I dug the Halo out again and it turned right on with 3 bars of power, jumped both cars a total of 7 times and it only went down to 2 bars of power.This item is a must have.Charge it up, throw it in your car and forget it.You never know when you need a DC outlet, flashlight, USB charger, or most importantly an instant jump start when nobody's around to lend a hand.I've considered buying another but this thing is so reliable and long lasting that I don't need another portable battery!