My very old and heavy jumper box stopped working last year and I had to buy a new one.  I bought a 1,000 watt one from Harbor Freight.  I have only had to use it once to jump start a nephew's Ford Escape - and the little jumper box started it instantly.  I have used the jumper box as a charger box when camping to recharge my phone and helmet radio.  It is amazing that this little light weight gizmo can start a full size car when needed!  After seeing it work my wife decided I needed to buy one for her car.........we still have jumper cables but never use them!

https://www.harborfreight.com/1000-peak-amp-lithium-ion-jump-starter-and-powe...

https://www.harborfreight.com/2000-peak-amp-lithium-ion-jump-starter-and-powe...

I have a Noco Boost XL (amazon). Charged it , put it behind the seat of the truck , at least a year later. Working car ship in Oakland I smoked my 50 lb company supplied jumper. At break went to my truck grabbed the Noco , after being uncharged for a year , it started 16 cars & trucks before it died.
It’s 5 years old still starts a dead car no problem. And also have a tire inflator too. It makes enough pressure to bead a m/c tire. Both in a small go bag , behind the seat.

I believe NOCO makes/sells good products.

I bought a NOCO charger/tender for charging the deep cycle battery in my trailer.  The thing has very impressive programs for maximizing the life of the battery.  It also has a program for reviving a compromised battery.

I have a top road service membership , but sometimes you got to GO NOW !
Stubborn and hella independent, excellent idea to keep both in the truck.
Nice to know road service is still a viable option.

A few years ago I picked up a supercapacitor jump box as opposed to a l-iion battry box. I wanted something that I didn't have to worry about making sure it was charged up. With a supercapacitor, you charge just before you use it. It gives about 5-10 seconds of cranking. Long enough to start the vehicle if its only problem is a low battery.

The interesting thing is that you can charge the capacitor from your own battery, as long as it is not completely flat. It takes a few minutes to charge it up. It will even charge from a computer USB connection, although it takes longer to charge.

The advantage is that it can be stored without worrying about keeping it charged up. Forget about it until you need it.

The disadvantages are the short cranking time. If your only problem is a low battery, it works well. If there is another problem causing you to crank and crank, it's not good for that. The other disadvantage is that it doesn't work as a secondary power source for other uses-- like charging your phone or other devices.

The good side is