Changing Car Battery is not a difficult task, but it is one that must be done properly. Learn how to Changing
battery by following these steps. A correctly performed Changing battery extends your vehicle's life while
keeping you and the environment safe.
Make sure the battery needs to be replaced
Make sure the battery needs to be replaced. You don't want to spend time and money
installing a new battery if the problem is not with the battery itself. Take the following
three things into consideration:
Look for sulfate build-up in the form of a whitish or blue residue around the terminal —
removing this can sometimes solve issues with a faulty battery. This residue may
indicate a bad seal around the battery terminals and is leaking the acid out onto the
terminals. Note: do not touch this powder with your bare hands, as it can often contain
dried out sulfuric acid which will begin to burn your skin.
Verify that the battery has been given the chance to recharge properly by driving
constantly for 30 minutes (with minimal electrical usage, including the air conditioner)
Finally, you should check the alternator. Some cars also have a battery meter, with the
engine running, the alternator usually maintains a charge close to 13.8 – 14.2 volts in a
properly functioning charging system. The battery should have 12.4 – 12.8 volts with the
engine off, and with no accessory load.
Buy the correct replacement battery
Buy the correct replacement battery. Find out what kind of battery you're replacing
(or the dimensions of your battery) and bring this, your car's make, model and engine
size information to a local auto parts store. This is important because automotive
batteries vary in size and electrical capacity and you will want to purchase a battery
which matches the size of the battery tray/support in your vehicle.
Set up a secure working environment
Set up a secure working environment. Park on a flat, level surface at a safe distance
from traffic, sparks or open flames. Put on the parking brake. Don't smoke, and make
sure any smokers in proximity to the working area know not to smoke as well.
Remember that electricity is not the only danger; batteries contain a sulfuric acid
electrolyte solution, which is highly corrosive (i.e. can burn your skin) and produces a
flammable hydrogen gas. Put on gloves and safety goggles.
Remove the cigarette lighter
Remove the cigarette lighter and plug the memory keeper into the lighter socket. A
Complementary metal–oxide–semiconductor (CMOS) will keep the PIN codes and
settings for radios and navigation systems from getting erased when you disconnect
the battery. If you don't have a memory keeper make sure you have all the PINs for your
electronic equipment before you start. You may wish to check your car manual to see
what devices may be affected.
Prop open the hood of your car
Prop open the hood of your car. After opening your hood, use the prop rod to keep your
hood open (Most newer cars have hoods that hold themselves up.
Be aware that some cars have batteries locate elsewhere, like in the trunk, so you may
not need to pop theb hood at all.
Locate the battery
Locate the battery. The battery should be located in an accessible part on either side of
the car's frame. The battery is a rectangular box with two cables attached to it. Some
European cars (some BMW's) have the battery under the matting in the trunk, some
vehicles can have the battery located under the rear seat, or some are located inside the
fender of the wheel well (some Chrysler's). The latter is often very difficult to remove.
Identify battery terminals
Identify battery terminals. Locate the positive and the negative terminals of the old car
battery. The positive terminal will have a plus sign (and is often red) and the negative
terminal will have a minus sign (and is often black).
Disconnect the negative terminal
Disconnect the negative terminal. Loosen the negative cable clamp with a wrench
(Usually 8mm or 10mm) and slide it off of the terminal. If the cables are unmarked,
label them so that they don't get mixed up (otherwise you may ruin your car's electric
system later on). It is also important that you disconnect the negative terminal socket
before the positive terminal socket. Otherwise, you may short circuit the positive
terminal to a grounded part of the car.
Disconnect the negative terminal
Remove the car battery
Remove the car battery. Unfasten the battery holder and remove any screws, clamps or
bars holding the battery in place. Carefully lift the battery out of the car. Remember that
a battery can weigh 30 to 60 pounds, or 13.5 to 27 kilos, so if you have any back
problems, get a helping hand.
Clean the terminal clamps and the battery tray
Clean the terminal clamps and the battery tray. You can use a baking soda solution and
a wire brush. If there's any severe corrosion to the terminal ends or the cables, consider
repair or replacement by a mechanic. Otherwise, let the area dry before moving onto
the next step.
Replace the battery
Replace the battery. Place the new battery where you just took the old battery out, with
the positive and negative terminals on the correct sides. Connect all the screws, clamps
or bars that may hold the battery in place.
Reconnect the positive terminal
Reconnect the positive terminal'. Tighten the clamps using a wrench.
Apply battery lithium grease
Reconnect the negative terminal. Tighten the clamp with the wrench.
Apply battery lithium grease
Apply battery lithium grease. Spray the terminals with lithium grease to prevent
Close the hood
Close the hood. Shut the hood of your car firmly and start your car. Check that all the
electronic devices are working properly. Remove any battery memory saver that was
installed to save the radio memory.
Close the Properly Dispose of the Old Battery
Dispose of the used battery at service garages, auto supply stores, and recycling centers.
There may be a small fee for the service, but throwing the battery away as normal
garbage is not an option.
In the US, most battery retailers charge a deposit on the battery, which will be refunded
with the return of an old battery.