If you're unfortunate enough to require a new battery you don't want to be adding to things by locking your radio too, so make sure you have your code available for when you've finished.

The roadster uses a very common battery found in alot of cars (makes a change for something to be standardised with the rest of the market), It can be bought in any motor factor under the UK part number: 063, this is a 12v 43Ah unit.

In order to access the battery, remove the bonnet bin first.

With the bonnet bin removed, you will now be able to locate the battery.

Be very careful to ensure that neither of the terminals come into contact with each other.

Disconnect the negative terminal first with a 10mm spanner.

Now remove the red capping on the top of the battery to reveal the positive terminal, disconnect this as well using a 13mm spanner.

Look down the back of the battery, You will see a hex bolt (shown in the picture below). This bolt secures the bracket that secures the battery to the floor pan so will need to be removed.

Once the bracket is removed remove the battery by lifting it upwards.

Install the new battery using this guide in reverse, making sure the positive terminal is connected first.

Once the new battery is fitted and working, take the car out for a drive (approx 30 minutes) just to top up any charge the new battery has lost from sitting on the shelf before you bought it.