I am ordering a Jackery portable power station....it will recharge my laptop, phone and provide power for a LED lamp for a couple of days.
Years ago I looked at one of those devices that would jump-start your car; I decided against it because it wasn’t something you just threw in the trunk (it lost its charge fairly quickly). A good idea, but at the time not worth the money.
In hindsight, it would have easily mounted on an ALICE pack frame with a cargo shelf; would power devices for a bit if camping...