Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Please note that it is not permitted to have referral links posted in your signature. Keep these links contained in the appropriate forum. Thank you.

https://www.boards.ie/discussion/2055940817/signature-rules

Battery problem, suggestions welcome

Options
  • 24-03-2008 3:32pm
    #1
    Beano
    Closed Accounts Posts: 3,357 ✭✭✭


    I bought a new battery and already it is flat. I tested it after i bought it and it was reading over 12V. I tested it again last night and it was reading around 12V so i wasnt worried. I tried to start it this morning and it wouldnt. Tested the battery again and it was reading only 5V. Any ideas how i can figure out why the battery is being drained so fast?


Comments

  • Options
    #2
    eringobragh
    Registered Users Posts: 3,668 ✭✭✭eringobragh


    Whats the reading when the cars running it should be 13 - 14v at least otherwise your alternators gone. Happened to me 2 weeks ago and i recommend ALMAX for a recon they done a great job on my primeras one!! Not sure how handy you are with car but i did it myself in half an hour and i'm no mechanic.


  • Options
    #3
    Beano
    Closed Accounts Posts: 3,357 ✭✭✭Beano


    Forgot to say i did test it with the engine running and it was reading over 12V so i'm sure the alternator is ok.


  • Options
    #4
    eringobragh
    Registered Users Posts: 3,668 ✭✭✭eringobragh


    What exactly was the reading if it was 12.5 then thats what my battery measures with the car turned off.

    Do you have an after market alarm??

    Should be 13.8 to 14.2 volts or somewhere in that region


    One Very Simple Alternator Test:

    1) Start Car and run at a normal idle.

    2) Connect a Voltmeter Directly Across the battery Terminals.

    3) Turn on Headlights to High Beam.

    4) check the battery Voltage.
    *** The Battery voltage Should read between about 13.8 to 14.2 volts. (Possibly up to 14.5 Volts.)

    5) Increase motor speed to about 1500 RPM. The Alternator should now produce a battery voltage between 14.2 and 14.6
    Volts.
    *** If it is Lower than 14.2 volts, the Alternator probably has one or more Bad Diodes.

    6) Now, Maintain the 1500 RPM and Turn off the Headlights. Run this test for One Full Minute.
    "The Battery Voltage should NEVER Exceed about 14.8 Volts".
    ***If it Does, the Alternators Voltage Regulator is probably Faulty, OVER CHARGING the Battery.


  • Options
    #5
    Beano
    Closed Accounts Posts: 3,357 ✭✭✭Beano


    I cant remember the exact reading but it was enough to tell me that the alternator is not a problem. The problem is that something is draining the battery.


  • Options
    #6
    eringobragh
    Registered Users Posts: 3,668 ✭✭✭eringobragh


    After market alarm? Cark Kit?? Bulb in boot not turning off..


  • Advertisement
  • Options
    #7
    Lucifer
    Registered Users Posts: 1,467 ✭✭✭Lucifer


    As with nearly every question that is asked here on boards, people come on saying there is a problem with my car, and thats about all the information that we get. Post the make, model, year, engine size for a start. From that we may be able to say more.

    Also has this problem just happened once? or did you get a flat battery, replace it, and now the new one is flat, in which case would indicate something staying on or not charging correctly. Possible causes could be boot light, glovebox light/ interior light. as suggested do you have a phonekit or alarm??


Advertisement