Ed;
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
-----Original Message-----
From: owner-land-speed@autox.team.net
[mailto:owner-land-speed@autox.team.net] On Behalf Of Ed Van Scoy
Sent: Wednesday, November 19, 2003 9:24 AM
To: land-speed@autox.team.net
Subject: Battery Help
Trying to order a new battery for my Harley, but the catalog
has ratings in CCA or amps, but not both. Does anybody know
how to convert amp-hrs to CCA? Or at least an approximation?
TIA
Ed
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