I tried jump starting my aunts car and failed. What did start the care was my cousins nektech jumpstart device. Why one and not the other?
I'm on vacation so test equipment is in short supply. The dead car wouldn't even provide dash lights when connected to boost vehicle. I figured it should have started on cable boost or at least get lights. I'm thinking ratty booster cables.
It seems reasonable a cable boost or jumpstart work the same way. Curious minds want to know.
I had to go back and try to determine why it didn't work. The picture is the connections of the four ends of the jumper cables. The cable is robust but the insulation wasn't stripped away before they were crimped. I had never used the cables before. I suspect they were a christmas present stuffed in the trunk of her car. No real gift when they don't work.
To quote the MythBusters: "Well theeeere's yer problem!"
I like those little jumpstart boxes. They seem to work well and take up very little space - less space than jumper cables.
i've also used one to power 12v LED lighting in a little camper, and also to test trailer lights (the father-in-law's boat trailer in salty water has failed a lot!).
It looks like you'd have to unclamp the jumper cable ends, strip the insulation, and then solder and crimp reassemble it all. I think some of the crimps do go over the insulation, but you would need the inner wire to make contact somewhere 
You might need a little propane torch like when you're soldering plumbing pipes.
I'd be tempted to just buy a jumpstarter instead... but then again, those cables have made it personal and require an attitude adjustment to show them who's boss! 
