I have one of these from Supercheap which about five years old by now and it still does the job well, however I do ensure it gets charged regularly.
As we have several vehicles, tractors etc., twin batteries are out of the question, so this gadget comes in handy.
Whenever we go away in any of our vehicles we always take it along, and as we have a few oldies on club plates it goes on any outings with them too.
It's not the be all and end all, but it's very handy.
SCA 12V Jump Starter - 8 Cylinder - Supercheap Auto
Cheers, Mick.

