There is a tight strap across the battery which is fully attached to a metal plate at one end and the other end is inaccessible, in the depths of the engine.

The metal plate is screwed in but there is no way I can reach the nut that holds it in place, if in fact you are meant to remove it at all.

How can I loosen the strap to get the battery out and a new one in?

Tim Eden, February 2008

Yes use a spark plug 16mm socket with a socket set also when you put strap back put the nut in your spark plug socket and tape nut around the socket so you don't lose the nut I used gaffa tape

Colin, December 2017

CUT THE STRAP whatever else you do. I don't know, but the only purpose of the strap seems to be to stop you changing the battery and instead take it to a Ford dealership.

There's no chance of the battery going anywhere. It's tucked up like a pig in a blanket.

Roger, November 2015

Kisses - Keep it Simple & Effective Solution (5 minutes or less).
1. Use a small torchlight to see the screw & tall thread at battery's side.
2. Spray WD40 on it (use red tube that comes with it). Wait small.
3. Get 16mm Spark Plug socket (temporary remove its inner plastic) and add wrench with 2 small wrench extensions and gently apply pressure.
Easy Peasy - no cutting ties etc. You can use a copper tube and washer to replace if you wish but its not really necessary.

BillStreetKa, February 2014

As I only needed to recharge the battery I left it in and used a screwdriver to lever the straps to one side for the middle two holes ...don't forget to disconnect leads first!
My socket set did't have a plug extension.

Peter Marsh, December 2010

I cut the strap too
Used large cable ties from the right hand side to make a 'chain' over the battery but leaving the left hand part of the strap and threading the last cable tie into a hole made in the strap... Doesnt look pretty, but works

Donald Toone, December 2009

Hi.
I used to have a ka and now have a street ka. I have just cut the strap with scissors both times and it has been problem free.
I was a little worried about doing that but it has been fine and the battery is such a snug fit and heavy that it doesn't roam around.
Hope this helps.

Stephen, October 2009

I FOUND AN OLD 5/8 SPARK PLUG SOCKET WHICH DID THE TRICK. OTHERWISE I WOULD HAVE BOUGHT A BOX SPANNER.

JONNYJONO, January 2009

Also the socket needs to have a long enough internal recess to allow for the length of thread - I wound up using a tool for removing spark-plugs as my socket set couldn't reach the nut.

Ed, February 2008

You need a socket set with an extention bar long enough to reach the bolt .

andybob, February 2008