Neil,
Thanks!! An excellent explanation of the battery ratings and their
effect on application. This is a keeper!
Tom, Redding CA - #216 D/CC
>>There is little relationship between CCA and amp-hours (A-H).
>>Cold Cranking Amps is influenced by a battery's internal resistance.
>>The lower the internal resistance, the higher the current it can
>>deliver to a load. Battery construction and battery type influence
>>internal resistance. More lead & short, heavy cell connections make
>>a lead-acid battery's internal resistance lower.
>>Even relatively small Ni-Cad batteries with vented-cell construction
>>typically have extremely high peak current capability due to their
>>very low internal resistance. Their amp-hour rating isn't high but
>>they can deliver a great burst of current for a short time. For
>>example, Ni-Cad missile batteries had a rating of only 4 Amp-Hours
>>but they could put out 18 amps for 6 minutes. Their short-circuit
>>current could fry a small screwdriver.
>>Amp-Hour ratings are based on the time it takes to discharge a
>>battery (to a certain voltage) with a lighter load. Batteries
>>optimized for A-H performance are like a deep-discharge battery
>>while batteries optimized for CCA are the types that are used for
>>starter motors. Some types are a compromise between the two.
>>The battery manufacturer should be able to furnish both CCA & A-H ratings
>>for their batteries.
>> Regards, Neil Tucson, AZ
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