In this video I’m taking a close look at the LokiThor J400 jump starter and seeing if it really lives up to the “powerfully compact” claim. I don’t baby-test this stuff—I put it on a real problem vehicle: my 1982 Ford F100 with a dead battery, and that truck is notoriously hard to start. So if a jump pack can handle that scenario, it’s already doing something right in my book. I walk through the jump start process and demo it in action, focusing on what matters in the real world: does it work when you need it, is it easy to use, and is it worth carrying in your rig as part of your emergency kit. Overall, I’ve been impressed with the J400’s performance on the F100 test. My main gripe is simple: I’d like to see it come with a protective case included, because that’s the kind of thing that helps a tool like this survive being tossed in a truck box or gear bin—but at least the case is available separately if you want it.