megawatt00 |
10-28-2008 06:12 PM |
Battery Q&A
I recently received a message from a member asking me some questions on the batteries in our trucks. He pm'd me because he felt that it was a foolish question to post a thread about. I told him that to me there are no "foolish" questions.
I decided to answer here for all of you. I hope that is of help.
Diesels are high compression engines and take alot of amperage to start.Just look at the size of your starter. Add to that you have 8 glow plugs. They are nothing more than electric heaters.
When it gets really cold or even chilly batteries actual start to lose some of their (CCP) cold cranking power It comes back when they warm up. (charging). .The colder it is the less efficiant the battery is.This is why batteries are rated in CCA {cold cranking amps) Remember the most difficult part of a battery's life is when you are cranking over the engine, where it receives no help from the alternator. That much amperage being sucked from the battery is incredibly hard on it, which is why there are two batteries to begin with.
The batteries are wired in parallel, not series, if wired in series you gain nothing in power just the voltage doubles.This is done so the load is distributed equally to both batteries. An old battery will always be weaker than a new battery. This causes strain on the new battery This is caused by it needing to compensate for the weaker old batter.The old battery will eventually draw the new battery to the same level, or possibly weaker than the used battery. The used battery will then have to compensate for the new battery until it becomes the weaker one again., This cycle will continually repeat itself until both batteries have no "life" left in them.
Another point to ponder is the connections. They must be good and clean. You can have the biggest batteries in the world but without the proper connections they aren't going to do you any good. Make sure there is no corrosion on the terminals or cables.If you replace a clamp and you strip back the cable and notice it "green" or "powdery" consider replacing the cable itself. This is a sign of corrosion, which equals resistance.When replacing a cable it is ok to go to the next larger size cable, (less resistance), but never drop down in size.(Resistance and amperage become an issue here) Corrosion or reaistance is not good, especially when you need maximum power from your batteries to your starter. This includes the grounds. Most people just look at it as 'it's only the ground" On a DC system the ground is just as important as the positive, The ground is the return path for the electricity. Electricity needs a complete path or circuit in order to work. So the ground is essential to the system as well.
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