Postby schmo9 » Fri Mar 09, 2012 3:25 am
Problem solved:
When I replaced the battery I put all my faith in the battery dealer and when I asked for a battery for a Pathfinder he looked up his chart and gave me an 096 battery (which is only the code for the dimensions of the battery by the way) and I went on my way. What he didnt tell me was that the battery only had 510 CCA....fine in normal weather but not enough get started when the temperature drops.
I done some research on batterys, which I suggest everyone does, and I went and bought an 096 battery with 720CCA and 76AH.
What a difference...never have I had it spin up so fast.
I done a lot of investigation into my Pathy before doing this....earth leads, alternator, starter motor off and stripped down and also the parasitic draw of 130mA (caused by the interior light circuit). This draw seems to be normal for my Pathy as I have been through the circuit and there are not shorts to earth or corrosion anywhere, but even so, with a 76AH battery I should only start to see problems from that after about 26 days...not next day!!!!
I know most of you will be aware of the need for a strong battery but for those who dont...when you replace your battery, understand what you need and go for one with the most cold cranking amps you can afford and fits your car.
Some info Ive learned:
What are CA's (cranking amps) & CCA's(Cold Cranking Amps)?
Cranking amps are the numbers of amperes a lead-acid battery at 32 degrees F (0 degrees C) can deliver for 30 seconds and maintain at least 1.2 volts per cell (7.2 volts for a 12 volt battery).
In other words, CA/cranking amps determine how much power you have to start your car in most climates. The basic job of a battery is to start an engine; it must crank, or rotate the crankshaft while at the same time maintain sufficient voltage to activate the ignition system until the engine fires and maintains rotation. This requirement involves a high discharge rate in amperes for a short period of time.
Since it is more difficult for a battery to deliver power when it is cold, and since the engine requires more power to turn over when it is cold, the Cold Cranking rating is defined as: The number of amperes a lead-acid battery at 0 degrees F (-17.8 degrees C) can deliver for 30 seconds and maintain at least 1.2 volts per cell (7.2 volts for a 12-volt battery).
In other words, CCA/cold cranking amps determine how much power you have to start your car on cold winter mornings.
What is Reserve Capacity?
Reserve capacity is the time in minutes that a new, fully charged battery will deliver 25 amperes at 80 degrees F and maintain a terminal voltage equal to, or greater than, 1.75 volts per cell. This rating represents the time the battery will continue to operate essential accessories if the alternator or generator of a vehicle fails.
Put another way, reserve capacity is a battery's ability to sustain a minimum vehicle electrical load in the event of a charging system failure. Under the worst conditions (winter driving at night), this minimum could require current for ignition, low beam head lamps, windshield wipers, and defroster while driving at low speeds.
Can different size batteries have the same capacity?
Batteries come in many different group sizes eg 096. A battery's group size simply determines it's length, width, height, and terminal configuration; this has nothing to do with a battery's capacity. Regardless of the group size, two batteries are equal in power if the CCA ratings are the same.
New technology enables a great deal of power to be put into smaller cases with today's new high capacity output design.
Simon
