Tim, Christmas of 2016 Ace Hardware had their compact jump start devices on sale. I bought some for my son's and two grandkids who are away at college. Recently one of my son's needed to jump an old car he still has in garage. He pulled out the jump start which hasn't been charged since Christmas of 2016 and it fired the car right up. I also keep one in my car and put in boat when I launch. Mine is very compact, about size of car owners manual or an old time country Bible. It is much easier to store and use than jumper cables and it will recharge of the engine alternator in no time.
You can catch them on sale for half price(~$50) and it is a great investment.

Course none of that matters if you forget to put the drain plug in.