I saw this advertised in January's Practical Classics. http://www.sealey.co.uk/plpagebuilder.a ... icleid=396
I bought one of those Lithium ion emergency jump start batteries for the boot of my daily driver last year. It's tiny and been used successfully for me and helping out the neighbours.
This Sealey item claims that it sucks the remaining life out of the dying battery in 2 minutes to then jump start the dead car. How does that work?