Testing gwiz electrics with 12v

Hi all,

Im planning an electric conversion on my K11 micra using a gwiz as a donor. The wiz has been sat with no batteries for a while and i wanted to test all the systems to make sure everything works. I am a bit reluctant to fork out on all new batteries and then find something doesn’t work so was wondering if i could power it up with some old (but useable) 12v batteries. Is this likely to fry the controller?