CA @ 32¡ãF VS CCA @ 0¡ãF
The most common rating is Cold Cranking
Amperes (CCA) @ 0¡ãF. This rating tells you
how many amperes a new battery at 0¡ãF can
deliver for 30 seconds, and maintain or exceed
1.2 volts per cell (7.2 volts for a 12 volt battery).
For example, a new 525 CCA battery should
deliver up to 525 amperes to the starter motor
at 0¡ãF for at least 30 seconds if required.
You may find a Cranking Ampere (CA)
rating on a battery. CA¡¯s are measured @ 32¡ãF,
instead of 0¡ãF. This rating will be about 10-30%
higher than the CCA rating, depending on the
design of the battery. Simply stated, this is
because electrons flow faster in warm temperatures
and slower in colder temperatures.
Having two different ratings, CA and CCA
can be confusing! The important thing to
remember is be sure you know which ratings
are being compared.You can¡¯t compare a
higher CA rated battery to a lower rated CCA
battery. It¡¯s an ¡°apples-to-oranges¡± comparison.
Always compare CCA to CCA or CA to CA...
Never mix the two!
BE CAREFUL! Batteries produce explosive gases.
Keep sparks, flames and cigarettes away from
batteries at all times. Protect your eyes at all times.
TESTING ¡ª Whether you are taking a load test
or open circuit voltage test or reading the specific
gravity of the electrolyte, be sure to follow all the
instructions that came with the tester and take
proper safety precautions. Always wear safety
glasses when working on or near batteries.
CHARGING ¡ª Batteries should be charged if the
hydrometer reading is below 1.225 SG or 12.4 open
circuit volts, or the load test is below 9.6 volts.
Always follow the charging instructions that came
with the charger. Wear safety glasses and keep
sparks, flames and cigarettes away from batteries
at all times.
JUMP STARTING ¡ª Never lean over battery when
jump starting or performing other maintenance.
Follow the proper instructions found on your
booster cable set or in the vehicle¡¯s owners manual.
Shield eyes and face from batteries at all times.
The most important function of the battery is to
provide power for cranking and starting the engine,
regardless of temperature extremes.
In the past, the cubic inch displacement of an
automobile engine was considered to be a key
factor in determining what cranking capacity was
needed from the battery in order to start the
engine. Cars built prior to the late1970¡¯s needed
approximately one cranking amp for each cubic
inch of engine displacement.
Today engine sizes are measured in liters rather
than cubic inches. They also are generally more
fuel efficient, with smaller engines providing more
horse power. This fuel efficiency is achieved by
using many components such as:
* Electronic Fuel Injection
* Electronic Ignition
* High Compression Ratios
However, each of these components increases
the cranking amperes needed to start the engine.
For example, a 1984 four-cylinder Ford Ranger
requires a 380 cold cranking amp (CCA) battery,
while a 2000 four-cylinder Ford Ranger requires a
540 CCA battery. Also, these newer, smaller
engines run at much higher temperatures.
Because of all the components and accessories
that can be combined, and each engine¡¯s unique
starting characteristics, it is impossible to use a
simple rule to estimate the required battery CCA
capacity. Therefore, you must rely on the BCI
Replacement Data Book, or owners manual, to
choose the correct CCA rating.
Never select a quality grade level lower than
the O.E. CCA rating. Remember that older cars,
extra accessories and severe climatic conditions
(extreme hot or cold) call for a more powerful
battery. In these cases, you should always select
a level above the O.E. requirement. Always select
a battery by CCAs...never months of warranty!
Warranties do not start engines¡ªCCAs do. Also
remember that you can never have too many
CCAs. But too few will shorten battery life because
the under-rated battery must work so much harder.
Another function of a battery is to provide emergency
power for ignition, lights, etc., in the event of
failure in the vehicle¡¯s battery recharging system.
The reserve capacity rating is defined as the number
of minutes a new, fully charged battery at 80¡ãF
can be discharged at 25 amperes and maintain a
minimum voltage of 10.5 volts for a 12-volt battery
or 5.25 volts for a 6-volt battery. Simply stated, the
reserve capacity rating is a relative measure of how
long you can drive to find a facility if your charging
system fails. Runtime is shorter at cooler temperatures
and longer at warmer temperatures. It also
changes with the load. At half the load, runtime will
more than double. At double the load, runtime will
be slightly less than half.
Marine Starting Service
When a battery is called upon to deliver several
hundred amperes of power to the starting motor, it
must be able to give up this power quickly...within a
few seconds. This power comes off of the surface of
the plates inside the battery. Therefore, a battery with
more plate surface and less resistance will deliver
more power than one with less plate surface and
That¡¯s why starting batteries are made with thinner
plates...because you only use the power off the
surface of the plates for starting the engine.
Trolling and/or Deep Cycle Service
However, a deep cycle battery is called upon to
deliver a long, slow discharge of fewer amperes...for
several minutes or hours...in a deep cycle application
such as running a trolling motor or marine accessory
loads (e.g. depth finders, fish finders, radios, radar,
lights, coolers, etc.)
In this case, the power comes from deep within
the plates, not merely off the surface, as in starting.
Therefore, the Deka Deep Cycle Series is specially
engineered with heavier, thicker plates with fiberglass
reinforcement, special power producing active
material, and special heavy-duty separators.
MARINE APPLICATIONS (con¡¯t.)
With these features, the battery can withstand
the potentially damaging effects of continually
being deeply discharged and recharged
over and over again. The unreinforced, thinner
plates of any starting battery can¡¯t stand this
deep cycling and will fail in short order.
Deep Cycle or Starting...
Which Should I Choose?
Ideally, you could have one battery for starting
and an auxiliary deep cycle battery for the
trolling motor and/or accessories. If however,
you can only have one battery on board, it
should be a deep cycle battery. The deep
cycle battery can handle the double duty of
starting, trolling/accessories very nicely.
However, a starting battery should not be
used for deep cycle service. It simply won¡¯t
hold up. If your deep cycle battery is expected
to perform the double duty of engine starting,
you must take special care not to discharge it
too deeply with the trolling motor and accessories.
Any battery that is discharged too
deeply will be unsuccessful at engine starting
until it is recharged.