WHAT TO LOOK FOR WHILE BUYING A NEW BATTERY?

Battery buying strategy will vary based on climatic conditions.In the colder climates,higher CCA ratings are more important; whereas, in a hot climate, a higher RC ratings are of more importance. requirement.

A. Cold Cranking Amps (CCA)
The most important consideration is sizing the battery's CCA rating to
MEET OR EXCEED, depending on the climate, the car's OEM cranking
requirements.
[CCAs] are the discharge load measured in amps that a fully
charged battery at 0 degrees F (-17.8 degrees C) can deliver for 30 seconds
while maintaining the voltage above 7.2 volts.
Batteries are sometimes advertised by their Cranking Performance Amps (CA)
or Marine Cranking Amps (MCA) measured at 32 degrees F (0 degrees C) or
Hot Cranking Amps
(HCA) measured at 80 degrees F (26.7 degrees C), which are not the same as
CCA.Do not be mislead by CA, MCA or HCA ratings.To convert CAs to CCAs,
multiply the CAs by .8. To convert HCAs to CCAs, multiply HCAs by 0.69.]
In hot climates, buying batteries with double or triple the CCA ratings
that exceed the OEM requirement is a WASTE of money. However, in
colder climates the higher CCA rating the better, due to increased power
required to crank a sluggish engine and the inefficiency of the cold battery.
As batteries age, they are less capable of producing CCAs.



[If more CCA capacity is required, two (or more) 12 volt batteries can be
connected in parallel. Within a BCI group size, generally the battery
with more CCA will have more plates because a larger surface area is
required to produce the higher current.]

B. Reserve Capacity (RC)
The second most important consideration is the Reserve Capacity rating
because of the effects of an increased parasitic (key off) load and in
emergencies. [RC is the number of minutes a fully charged battery at 80
degrees F (26.7 degrees C) can be discharged at 25 amps until the voltage
falls below 10.5 volts.] More RC is better in every case! In a hot
climate, for example, if your car has a 360 OEM cranking amp requirement,
then a 400 CCA rated battery with 120 minute RC with more electrolyte
would be more desirable than one with 1000 CCA with 90 minutes of RC.
[If more RC is required, two six volt batteries can be connected in series
or two (or more) 12 volt batteries can be connected in parallel. Within a
BCI group size, generally the battery with larger RC will weigh more
because it contains more lead.]

C. Type
The two most common types of CAR batteries are low maintenance
(non-sealed) and maintenance free (non-sealed or sealed). [The low
maintenance batteries have a lead-antimony/calcium (dual alloy or hybrid)
plate formulation; whereas, the maintenance free batteries have a
lead-calcium/calcium formulation.] The advantages of maintenance free
batteries are less preventative maintenance, longer life, faster
recharging, greater overcharge resistance, reduced terminal corrosion and
longer shelf life, but are more prone to deep discharge (dead battery)
failures due to increased shedding of active plate material.In hot
climates, buying non-sealed batteries is recommended because a sealed
battery will NOT allow you to add water when required or to test the
specific gravity with an external hydrometer.Some manufacturers introduced
a third type of car battery, "dual", that Combined a standard battery with switch
able emergency backup cells. For about the same cost a better approach was
to buy two batteries and isolate them.In the future, you can expect to see more
expensive valve regulated (gel cell and absorbent glass mat (AGM) .This is because
car manufacturers want to extend their "bumper-to-bumper" warranty periods or as
the batteries are relocated from under the hood to avoid temperature extremes.
For excessive vibration applications, it is best to buy a commercial or AMG battery.
Car batteries are specially designed for high initial cranking amps
(usually for five to 15 seconds) to start an engine; whereas, deep cycle (or marine)
batteries are designed for prolonged discharges at lower amperage.
A "dual marine" battery is a compromise between a car and deep cycle battery;
however, a CAR battery will give you the best performance
in a CAR. For RVs, a car battery is used to start the engine and a deep
cycle battery is used to power the accessories. [The batteries are
connected to a diode isolator and both are automatically recharged by the
RV's charging system when engine is running.


D. Size

Manufacturers build their batteries to an internationally adopted Battery
Council International (BCI) group number (24, 26, 70, 75, etc.)
specification, [which is based on the physical case size, terminal
placement and terminal polarity.] The OEM battery group number is a good
starting place to determine the replacement group. Within a group, the
CCA and RC ratings, warranty and battery type will vary in models of the
same brand or from brand to brand. Batteries are generally sold by model,
so the group numbers will vary for the same price. This means that for
the SAME price you can potentially buy a physically larger battery with
more RC than the battery you are replacing, e.g. a 34/78 group might
replace a smaller 26/70 group and give you an additional 30 minutes of RC.
If you do this, be sure that the replacement battery will fit, the cables
will connect to the correct terminals, and that the terminals will NOT
touch the hood when closed.

BCI and the battery manufacturers publish application guides that will
contain the OEM cranking amperage requirements and group number
replacement recommendations by make, model and year of car, and battery
size, CCA and RC specifications. Manufacturers might not build or the
store might not carry all the BCI group numbers. To reduce inventory
costs, dual terminal "universal" batteries that will replace several
group sizes are becoming more popular and fit 75% or more of cars on
the road today.

Battery manufacturers or distributors will often "private label" their
batteries for large chain stores. Below is a list in alphabetical order
of the largest domestic battery manufacturers/distributors in North
America and my understanding of some of their brand names, trademarks
and private labels.

E. Freshness

Determining the "freshness" of a battery is sometimes difficult. NEVER
buy a battery that is MORE than SIX months old because it is starting to
sulfate. [Sulfation occurs when lead sulfate can not be converted back to
charged material and is created when discharged batteries stand for a long
time or from excessive water loss.] The date of manufacture is stamped on
the case or printed on a sticker. It is usually a combination of alpha
and numeric characters with letters for the months starting with "A" for
January (generally skipping the letter "I") and digit for the year, e.g.,
"J6" for September, 1996. Like bread, fresher is definitely better.

F. Warranty

As with tyre warranties, battery warranties are NOT necessarily indicative
of the quality or cost over the life of the car. Most manufacturers will
prorate warranties based on the LIST price of the bad and replacement
battery, so if a battery failed half way or more through its warranty
period, buying a NEW battery outright might cost you less than paying the
difference under a prorated warranty. The exception to this is the free
replacement warranty period. This represents the risk that the
manufacturer is willing to assume. A longer free replacement warranty
period is better and is usually an indication of the quality of the
battery.

Caution: Batteries contain a sulfuric acid electrolyte which is a highly corrosive poison, that will produce gasses when recharged and explode if ignited.When working with batteries, you need to have plenty of ventilation, remove jewelry, wear protective clothing and eye wear (safety glasses), and exercise caution. Whenever possible, please follow the manufacturer's instructions for testing, jumping, installing and charging.