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RPM + Battery Power

Discussion in 'Motors' started by peter212693, 25 Mar 2006.

  1. peter212693

    Wise Guy

    Joined: 28 Jan 2005

    Posts: 1,690

    Location: Southport

    Hi all

    When I am driving during the day my car sits at just on or just over the 1000 rpm mark, I have my radio and my blowers on sometimes. Now at night when I have them on + my lights it will drop to about 700-800 and the car feels like it does just before it stalls but it will drive fine once I increase the rpm with my accelerator. I have a little thing on my battery and it says it’s charged but probably inaccurate, its 3years + old now.

    Is this my problem, an uncharged battery?
     
  2. SgtTupac

    PermaBanned

    Joined: 3 Oct 2004

    Posts: 2,859

    Location: UK

    It drops because you are "loading" the car. Your draining battery power causing the alternator to run more power. its ok :)
     
  3. peter212693

    Wise Guy

    Joined: 28 Jan 2005

    Posts: 1,690

    Location: Southport


    I have not noticed it before only recently, will charging the battery help?
     
  4. moss

    Soldato

    Joined: 1 Nov 2002

    Posts: 6,487

    Location: South Shields

    No the alternator should be doing that for you, its probably the alternator or battery on the way out.
     
  5. peter212693

    Wise Guy

    Joined: 28 Jan 2005

    Posts: 1,690

    Location: Southport


    Which is it most likly to be the battery was bought in 2002 and i dont know about the alternator. The car is "P Reg" so 96-97
     
  6. SgtTupac

    PermaBanned

    Joined: 3 Oct 2004

    Posts: 2,859

    Location: UK

    I take it you got a Multimeter, start your car and check the voltage across the battery, when its running it should be about 14v, when engine is not running it should be around 12v :)
     
  7. Dr Who

    Sgarrista

    Joined: 11 Nov 2004

    Posts: 8,148

    Location: Wiltshire

    if its a fuel injection car (likely) the idle control valve may be faulty

    :(
     
  8. peter212693

    Wise Guy

    Joined: 28 Jan 2005

    Posts: 1,690

    Location: Southport


    I take it thats not good :( and yes its an injection
     
  9. -Mike-

    Capodecina

    Joined: 22 Dec 2002

    Posts: 10,166

    Location: Minehead

    My mates swift does this also, but with lots of draw the alternator/battery at night it will stall if you let it idle. Its fine during the daytime and holds the revs. I'd say get your battery tested and if you have a multi-meter as mentioned check your voltages. It should be able to hold a reasonable figure.

    I'm not too sure on my alternator but with lights on, heater, rear demister fog lights and stereo when driving it will hold 14.