Battery Maintenance.

The battery is one of the most neglected items in a motor car. Everyone just expects to jump in the car, turn the key and start the engine. The battery has quite a few important functions to perform. These are:

  1. Operate the starter motor
  2. supply voltage for the ignition system
  3. supply power to the fuel injection system (if fitted)
  4. provide electrical energy to components that need it and
  5. store electrical energy when the engine is not running

to mention only a few. The electrical system plays a big part in engine tuning. If there is a problem with the battery or charging system then tuning the engine cannot generally proceed until the fault is rectified. If the battery is not maintained regularly then somewhere down the track expect to be stranded waiting for someone to jump start you. All that is required is a weekly check for the following:

  • Check the cleanliness of the top of the battery
  • checking and cleaning the battery terminals
  • checking the electrolyte level if an old style acid battery is used
  • Inspecting the case for physical damage

Safety Note: Lead acid Batteries contain sulphuric acid which can cause severe burns or blindness if it comes in contact with the eyes. Wear appropriate PPE when handling batteries.

Lets discuss the cleanliness first. When the top of the battery is covered in dirt, corrosion or electrolite, it needs to be removed. All these contaminants can lead to electrical tracking and power drain from the battery. The terminals should be tight and corrosion free. A caustic soda solution in warm water poured over the terminals will neutralise any acid on the battery or posts. Be careful not to get any into the battery cells when you do this. Dry the battery after cleaning and be sure to flush the contaminants away from the chassis below the battery, otherwise the chassis will corrode. Plenty of water will dilute the contaminants.

To clean a battery terminal correctly will require you to remove the cables from the terminal posts. Now on modern vehicles this can affect other systems. There is a device called a memory saver that can be plugged into the cigarette lighter or the OBD2 connector that will prevent any problems that a battery disconnect may cause. Always disconnect the negative terminal first and re-install it last.

Get yourself a proper terminal cleaner, they are dirt cheap and are the best way to clean terminals without damaging them. When reconnecting the terminals apply a small amount of petroleum jelly to the posts and terminals. Tighten the bolts firmly. The top photo is just a cheap terminal cleaner and does the job nicely. For terminals that are badly damaged you will need a reamer type tool more appropriate for trimming the posts and terminals. (bottom photo)

Check the cell electrolite levels as per the below diagram, this is the level Century Batteries recommend for their batteries. The high level shown is absolute maximum. When you are topping up the cell stop when the water just touchs the bottom of the fill ring in the well. If you go even a few millimetres over this level you may end up with electrolite overflow from the cell cap during high charging rates from the alternator. Also you should check with the battery manufacterer just to check if they recommend this level for their batteries. Some manufacturers stipulate that the level should be 15mm above the plates. In this case the level is no where near the fill ring.

If you want maximum life from your battery, use de-mineralised or distilled water. This can be purchased at most auto spare parts outlets.

Inspect the case of the battery for damage such as the case may be swollen or cracked. This may indicate that there is an underlying problem in the charging system and will need to be rectified ASAP.

OK. I have covered the simple steps that you can do on a regular basis to get the most out of your battery and possibly avoid the road side jump start at the most inconvenient time.