CORRECT OPERATION
Use a battery with the highest practical amperage rating (above 500
Cold Cranking Amps) for easy starts in either warm or cold weather. Refer to
your owner's manual to determine the manufacturer's recommended amperage rating.
Use this figure as a minimum, especially if your car endures a very cold
winter. The extra power will minimize starter wear and cold engine part wear
since the engine will "catch" sooner with faster cranking action.
Furthermore, a powerful battery helps provide maximum spark inside the
cylinders, thus permitting complete combustion and minimal deposits. Choose a
battery with a high reserve capacity and long warranty as well.
Remember that the outside temperature will affect the power available from the battery. The battery produces 100% (maximum) power at 80° F. The power decreases to 65% at 32° F., 40% at 0° F. and 18% at -20° F. This is the main reason why it is more difficult to start an engine in cold weather; the battery is considerably weakened. See the graph below for a comparison.
