I have an 800amp Schumacher Jump Starter/Power pack for sale. Model SL1315.
I bought it a few years ago when I had a weak battery in my Jeep and only used it twice. After sitting in my closet for about a year, the internal Lithium Ion Battery still had a 99% charge on it. Comes in original box with manual, battery clamps, charging cable, and carry bag. This is designed to be used with vehicles with V8 engines or smaller. You can also charge smartphones, laptops, and tablets with it when needed. Has two USB ports: 2.4A and Qualcomm Quick Charge 3.0A. Has built-in LED light and lighted digital display to show charge % of the unit.
The box claims you can perform 25 jumpstarts on a full charge. I think I paid $90 at Walmart three years ago and would pass it on to you for $50. Thanks for looking and message me here on BisMan if you are interested.