A General Guide On How To Replace A Car Battery.
This is a general guide on how to replacing a car battery, you should always check the manufacturers recommendations on the best way to change a car battery on your particular vehicle type.
Common Tools You May Require
- Ratchet and socket set ( 8mm, 10mm, 12mm, 13mm)
- Spanners (8mm, 10mm)
- External Power Backup Connector
Confirm You Have The Correct Battery
The most common locations for car batteries are , under , the bonnet, the seat or in the boot. Before you attempt to disconnect the old battery make sure you have the correct battery to replaace it with.
Most car batteries have a label which will have the battery type and its specifications
Important if the current battery fitted is an AGM, EFB type battery it must be replaced with the same type and not the standard lead acid type.
Most modern vehicles can be very electrical dependent and disconnecting the old battery without connecting a backup power supply, could mean the loss of vehicle electrical settings eg (radio codes, clock, window, and other settings). It is advised to check with the manufacturer or ensure you have the ability to reset any settings lost.
If your vehicle is fitted with stop/start technology then it is possible that the new battery may need programming into the vehicle, a specialist tool would be required.
Step 1. Make Sure Everything is Off.
Remove the keys from the ignition and make sure all accessories , lights (interior and exterior), radio, etc are off.
Step 2. Remove Car Battery Hold Down.
When you have located the battery, you will most likely find that the battery will be held down with either a bracket at the base or a bar across the top, If they look corroded, spray some WD40 on first before attempting to undo.
The most common nuts/bolts that are used are 8mm,10mm,12mm,13mm, you may need a ratchet and deep socket.
Step 3. Connect External Power.
At this point, you may want to connect external power to the vehicle to try an maintain the electrical settings while you change the battery, follow the battery memory instructions on how to connect. If your vehicle battery is completely dead or in a very low state electrical settings may have already been reset, in which case connecting external power will make no difference.
Step 4. Disconnecting And Removing The Old Car Battery
IMPORTANT ! If you have connected external power, when you disconnect the terminals they will still be powered, you must ensure they do not come into contact with any metal surface. Cover the terminals with a non conductive material.
Most battery terminals can be undone with either a 10mm or 13mm spanner (some can be smaller). Some cars can have quick release terminals fitted
4a. Disconnect The Negative Terminal First
The first terminal to remove is the negative, this should have the (-) symbol on the lead or on the actual battery itself.
4b. Disconnect The Positive Terminal Second
The next terminal to be disconnected is the positive terminal, this should have the (+) symbol on the lead or shown on the battery itself.
Now that you have the terminals disconnected, place them out of the way making sure they do not come into contact with another metal surface. Some car batteries have a ventilation pipe connected, this needs to be disconnect aswell.
You should now have full access and be able to lift the battery out.
Step 5. Installing And Connecting New Car Battery.
Before you place the new battery back into position, make sure that the battery area is clean and clear and the terminals are not in the way. You should now be able to place the new car battery back in easily . The procedure is the basically the same as disconnecting but in reverse.
5a. Connect The Positive Terminal First.
Once the car battery is in place you can now connect the terminals, The first terminal to connect is the positive terminal (+). Once connected make sure to tighten and secure the terminal.
5b. Connect The Negative Terminal Second.
Next connect the negative terminal (-), once it is connected make sure to tighten and secure.
Once you have the terminals connected and secure, make sure to also connect the ventilation pipe if your vehicle type had one fitted.
Step 6. Disconnect External Power. (Skip If No External Power Connected)
Important! Do not attempt to turn on the ignition or start the car with external power still connected.
Now that you have the new battery fitted and connected, you need to disconnect the external power if you had it connected.
Step 7. Start The Vehicle
Once your happy that everything is in place and any external power is disconnect, you can now attempt to start the vehicle. Once started you may wish to use a multimeter to check the charging system is working how it should.
Step 8. Refit The Car Battery Hold Down.
Hopefully everything is as it should be and the vehicle has been started and systems checked, you can now refit the battery hold downs to make sure it is secure in its position.
We hope you found this general How To Replace A Car Battery Guide useful, if for any reason you are not confident in replacing or what your exact vehicle requirements are, please contact a battery replacement specialist or vehicle manufacturer . Car Battery Assist provides a mobile car battery fitting service in Watford, Harrow, Hemel Hempstead and St Albans, you can find out more about our service here
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