Dead battery?

I own a 1998 Jeep Cherokee XJ 4X4 , the other day I lost all power to my accessories and my vehicle died shortly after. It turned out that the battery was completely drained. I had the battery charged and checked at a local parts store and it was fine. I rechecked it at home and confirmed that it was fine. I pulled the alternator and had that checked, it was fine. I was told that it may be that my cables are bad. I checked them with a multimeter and all seemed to carry a current through them. I checked the fuses in the fuse box under the hood and all were intact. Should I replace my battery cables even though they checked out fine? What kind of reading should I be looking for on the multimeter? Is there something else that I should check? Any help would be greatly appreciated.

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4 Responses to Dead battery?

  1. rickpeet June 6, 2010 at 7:17 pm #

    Like all rechargeable batteries, a car battery can be over charged. When a car is running the alternator is continuously generating current. To prevent the battery from being over charged people use whats called a "regulator" to determine if the bettery needs to be charged or not. The output of the alternator goes into the regulator and the regulator connect to the battery to charge or not charge the battery depending on its current state.

    Regulators often go bad. You may want to check this. Although it might not be the problem it seems you’ve checked just about everything else except the wires. If there is a short in a wire your better off going to a professional.

    If you use a multimeter on your cables you should check that the DC resistivity is 0 ohms.

    You might also think about checking your "coil". This is a voltage converter that transforms your regular 12V to 40,000 V for the spark plugs. Sometimes these short out. You can check this by disconnecting the unit and following an owners manual to check the various impedance (resistivity) of the terminals.

    Also, if your car died after your electronics was on, that would suggest the battery is not the problem at all. Once a car is started the whole vehicle operates on the alternator power only.

    Good luck.

  2. golden holden June 6, 2010 at 7:17 pm #

    Maybe you should wait and see if everything is OK, if not try replacing the battery first.

  3. It All Matters.~☺♥ June 6, 2010 at 7:17 pm #

    I would rough up the connections where the cables connect to the battery, the engine Ground, and the starter. You may want to replace the battery terminal bolts as well. Sometimes they feel tight but due to corrosion are actually not tight enough. Last, I would remove the starter, and rough up the engine block, and starter mating surfaces. (By rough up I mean to use sand paper to scratch the surface.)

  4. Pedro S June 6, 2010 at 7:17 pm #

    replace battery if u still have problem…if cables r allright why replace them…once a battery is killed it often is never the same..what voltage is alt putting out? should b 14 or so… check voltage at battery with engine running..should be 12 or more