Stuck battery bolt

[Grahamm]

"It has a Phillips head cross in the top, so I tried using that, but it started to sheer..."
Now I don't want to insult you, and I'm only posting this because I've made this mistake myself. But are you using a pozidriv screwdriver?

Hmm, you may have a point(!) there, I thought the Phillips driver had the blunt tip, but I've just checked and it seems that the Pozidriv one is blunt and the Phillips one is pointy.

In any case, thank the gods for WD-40, after a bit of wiggling of the battery bracket I did manage to make enough space get the molegrips on the head and, after a little resistance, it started to unscrew.

Interestingly, even though there was a bit of corrosion on the head, it seems to have only been a patina and the rest of the bolt looked clean, so maybe the person who tightened it after they'd added the Optimate connector just did it up *really* tight.

Actually the Optimate came in useful for something else too, I couldn't get enough purchase on the battery to get it out of the holder, but then I had a brainwave and fixed the "clip-on" charging clamps from the Optimate onto the terminals and that let me lift it out

So anyway, now everything is back in place and it's running again, so thanks to everyone for their help and advice :thumbup