How does a captive nut hold a battery in place?

It is held in place by what seems to be two captive bolts fixed from under the battery box, bar put on top, then two nuts holding it down. The back of the captive bolt is hidden within the battery box, and the damn bolt keeps turning when I try to remove the nut. It must be rusted on (nut to bolt), and broken free from inside the battery box.

What to do if a battery nut breaks?

Cut it off, remove the clamp pieces and replace them. Or take battery back to Halfords for a refund and get RAC to do it. The two nuts can be seen on the right the photo, locking the bar down on the battery. The bolt is a captive bolt (or is meant to be!), and the bolt head is not accessible. If you cut the top off, the bolt can be removed.

How to remove a seized / broken captive nut / bolt?

Undo the one nut that will undo then bend the battery clamp bar up to get the battery out, then you can get mole grips on the loose bolt shaft. Both the captive bolts are buggered. I cannot hold the threaded shaft and undo the nut, nothing seems to hold well enough, can’t get purchase on the threads.

How do you get an old battery out of a battery?

Problem is trying to get the old one out of the battery box. There is a bar on the top, across the battery to keep it in the box. It is held in place by what seems to be two captive bolts fixed from under the battery box, bar put on top, then two nuts holding it down.

Can a broken nut be removed from a battery?

It must be rusted on (nut to bolt), and broken free from inside the battery box. I tried to file down two sides of the bolt so that I could hold it still with some grips whilst turning the nut to try to break it free, that is not working.