FLUID LEVEL/SPECIFIC GRAVITY
Except Maintenance-Free Batteries
See Figures 1, 2 and 3
Check the battery fluid level on all serviceable batteries at least once a month, more often in hot weather or during extended periods of travel. The electrolyte level should be up to the bottom of the split ring in each cell. Most batteries are equipped with an eye in the cap of one cell. If the eye glows or has an amber color to it, this means that the level is low and only distilled water should be added. Do not add anything else to the battery. If the eye has a dark appearance the battery electrolyte level is high enough. It is also wise to check each cell individually.
At least once a year, check the specific gravity of the battery. It should be between 1.20-1.26 in. Clean and tighten the clamps and apply a thin coat of petroleum jelly to the terminals. This will help to retard corrosion. The terminals can be cleaned with a stiff wire brush or with an inexpensive terminal cleaner designed for this purpose.
If distilled water is added during freezing weather, the car should be driven several miles to allow the electrolyte and water to mix. Otherwise the battery could freeze.
If the battery becomes corroded, a solution of baking soda and water will neutralize the corrosion, then the solution should be rinsed from the battery using cold water. Before applying the solution, make sure that the fluid caps are securely in place in order to prevent contaminating the electrolyte.
Some batteries were equipped with a felt terminal washer. This should be saturated with engine oil approximately every 6,000 miles. This will help to retard corrosion.
If a fast charger is used while the battery is in the car, disconnect the battery before connecting the charger.
Keep flame or sparks away from the battery; it gives off explosive hydrogen gas.Maintenance-Free Batteries
See Figures 4, 5, 6, 7 and 8
All later model cars are equipped with sealed maintenance-free batteries, which do not require normal attention as far as fluid level checks are concerned. However, the terminals require periodic cleaning, which should be performed at least once a year.
The sealed top battery cannot be checked for charge by checking the specific gravity using a hand-held hydrometer, since there is no provision for access to the electrolyte. Instead, the built-in hydrometer must be used in order to determine the current state of charge:
- If the indicator eye on top of the battery is dark, the battery contains sufficient fluid. If the eye is light, the electrolyte fluid is too low and the battery must be replaced.
- If a green dot appears in the middle of the dark eye, the battery is sufficiently charged. Proceed to Step 4. If no green dot is visible, charge the battery as in Step 3.
- Charge the battery referring to the charging rate amp/time chart for the necessary time span and rate of charge.
It may be necessary to tip the battery from side to side to get the green dot to appear after charging.
- Connect a battery load tester and a voltmeter across the battery terminals (the battery cables should be disconnected from the battery). Apply a 300 amp load to the battery for 15 seconds to remove the surface charge. Remove the load.
- Wait 15 seconds to allow the battery to recover. Apply the appropriate test load, as specified in the chart or on the battery label, for 15 seconds while reading the voltage. Disconnect the load.
- Check the results against the minimum voltage chart. If the battery voltage is at or above the specified voltage for the temperature listed, the battery is good. If the voltage falls below what's listed, the battery should be replaced.
CABLES AND CLAMPS
See Figures 9, 10, 11, 12 and 13
In order to avoid the possibility of accidentally grounding the car's electrical system always remove the negative battery cable first. Failure to do so could allow a spark to occur exploding battery gasses and cause personal injury.
Once a year, the battery terminals and the cable clamps should be cleaned. Loosen the clamps and remove the cables, negative cable first. On batteries with posts on top, the use of a puller specially made for the purpose is recommended. These are inexpensive, and available in auto parts stores. Side terminal battery cables are secured with a bolt.
Clean the cable clamps and the battery terminals with a wire brush, until all corrosion, grease, etc. is removed and the metal is shiny. It is especially important to clean the inside of the clamp thoroughly, since a small deposit of foreign material or oxidation will prevent a sound electrical connection and could inhibit both starting or charging. Special tools are available for cleaning these parts, one type for conventional batteries and another type for side terminal batteries.
Before installing the cables, loosen the battery hold-down clamp or strap, remove the battery and check the battery tray. Clear it of any debris, and check it for soundness. Rust should be wire brushed away, and the metal given a coat of anti-rust paint. Reposition the battery and tighten the hold-down clamp or strap securely, but be careful not to overtighten the retainer and crack the battery case.
After the clamps and terminals are clean, reinstall the cables, negative cable last. Never hammer on the clamps to install. Tighten the clamps securely, but do not distort them. Give the clamps and terminals a thin external coat of grease after installation, to retard corrosion.
Check the cables at the same time that the terminals are cleaned. If the cable insulation is cracked or broken, or if the ends are frayed, the cable should be replaced using a new part of the same length and gauge.
Keep flame or sparks away from the battery; it gives off explosive hydrogen gas. Battery electrolyte contains sulfuric acid. If you should splash any on your skin or in your eyes, flush the affected area with plenty of clear water; if it lands in your eyes, get medical help immediately.
When it battery replacement becomes necessary, select a battery with a rating equal to or greater than the one which was originally installed. Deterioration and aging of the battery cables, starter motor, and associated wires makes the battery's job harder in successive years. The slow increase in electrical resistance over time makes it prudent to install a new battery with a greater capacity then the old. Details on the role the battery plays in the vehicle's electrical systems are covered in Engine & Engine Overhaul of this guide.
- Carefully disconnect the negative battery cable from the battery terminal.
- With the negative battery cable disconnected and out of the way, carefully disconnect the positive cable from the battery terminal.
- Loosen the nut and/or bolt retaining the battery retainer strap or clamp. Remove or reposition the battery retainer.
- Wearing an old pair of work gloves or using a battery lifting tool to protect from any remaining battery acid, carefully lift the battery out of the vehicle and place it in a safe location. Be sure to keep the battery away from open flame and to protect surrounding areas from acid.
- Inspect the battery tray and cables for damage or corrosion. As necessary, clean or repair the tray and cables.
- Carefully lower the battery into position in the tray, making sure not to allow the terminals to short on any bare metal during installation.
- Position and secure the battery retainer strap or clamp.
- Connect the positive battery cable to the battery terminal.
- Connect the negative battery cable to the battery terminal.