The battery provides the life blood of your Ford Ka. Even though the engine powers the car, without the battery to power the starter and keep the car's computer running, your Ka is little more than an expensive yard ornament. Proper maintenance can extend the life of your battery, but sooner or later it will need replacing. Once you've tested the battery and eliminated other sources of battery problems like the alternator or the battery cables, it's time to pull out the old battery and put in a new one.
Open the bonnet.
Loosen the nut on the negative battery terminal with a socket and remove the negative battery cable from the battery. The negative terminal is marked with a minus sign.
Loosen the nut on the positive battery terminal and remove the positive battery cable. The positive terminal is marked with a plus sign. Don't touch the positive terminal with a tool at the same time you are touching the negative terminal or the vehicle's frame.
Loosen and remove the bolt holding a strap and clamping the battery in place with a box wrench. The bolt is located to the side of the battery. Remove the strap holding the battery in position.
Grasp the battery with a battery lifter and lift it free of the engine compartment. Place it somewhere safe until you can take it to be recycled.
Lower the new battery into position with the battery lifter. Place the strap around the battery and replace and tighten the clamp bolt to hold it in place.
Place the positive battery cable clamp over the positive terminal and tighten the nut to make a good connection. You should not be able to move or twist the cable.
Place the negative battery cable clamp over the negative battery terminal. Tighten the nut to make a solid connection.
The clamp bolt holding the strap around a Ford Ka battery can be hard to reach. If you don't have a box wrench, you can use a spark plug socket with an extender.
Touching both battery terminals or the positive terminal and a ground can cause electric shock, sparks or an explosion. Use care when working around a live battery.