Once upon a time when a battery cable became corroded and unusable, replacing it was a fairly simple job. In most cars today, the battery cables are part of the wiring harness and cannot be replaced individually and to compound the problem, the terminal ends are not always lead, but metal which will not hold up well with corrosion. It is not unusual to see these cables sell for over $800 and require many hours to install.
Battery corrosion is the main cause of cable failure and will in time completely eat through the battery cable clamps used on the newer cars and should be attended to as soon as it's noticeable. Maintenance can really save money as well as prevent a call for a tow truck.
Inspect your battery cables periodically for any corrosion and take care of it as soon as its visible!
Servicing the Battery
If there is corrosion on the outside of the terminal, it has probably accumulated between the cable clamp and the terminal. To clean this, the cables need to be removed from the battery and both the clamps and terminals need to be wire brushed until shiny. Don't breathe the dust, It is very corrosive.
If its a top post battery install battery protectant pads on the terminals below the battery cables. This will help prevent gases from getting back to the terminals. A little battery protectant spray on the terminals is a good idea also.
Note: disconnecting the battery may cause you to lose your radio presets and possibly cause the vehicle to run different for a little while as the computer relearns.
Acid residue or a build up of dirt on the battery case can cause a small electrical discharge and weaken the battery, so it should be cleaned off also. Its a good idea to remove the battery and clean the battery tray, as acid running down it can cause it to eventually rust out.
Facts about battery cablesBattery cables are made of copper conductor which provides maximum power from the battery to the starter and is the best carrier of electricity. However, copper is susceptible to corrosion. A corroded cable will introduce resistance to the starting system and diminish the battery's ability to deliver maximum starting power. Over an extended period of time, this will not only wear the battery down but also put a strain on the entire starting system.
All automotive batteries contain a highly corrosive material known as electrolyte or acid. This material is necessary for a battery to perform. Unfortunately, this same material acts as a catalyst for corrosion. This occurs because the seal between the battery housing and the post will vent a small amount of acid fumes. These fumes, when combined with humidity, heat, dirt, and other chemicals (anti-freeze. grease, and oil) accelerate the corrosion process.
Corrosion comes in many forms, some you can see and others you cannot. Many times, a corroded battery cable is replaced with a temporary repair terminal. Corrosion that can be seen on the surface of copper will also be under the surface as well as working its way underneath the jacketing inside the cable. Proper repair should include the installation of a sealed custom battery cable as well as the use of a cleaning brush to clear the battery post of any corrosion and assure proper contact between the battery cable terminal and battery post.