Halfords 3 year battery

Discussion in 'Car and Van Talk' started by tore81, Dec 30, 2016.

  1. ramseyman

    ramseyman Screwfix Select

    If the alternator is found to be ok you might get an entirely different response at a different branch of Halfords.
  2. nigel willson

    nigel willson Screwfix Select

    I have two batteries on my 15 year old transit ex BT.had them changed last year. Both were original batteries! Just started to play up in the cold.
  3. tore81

    tore81 Screwfix Select

    RAC have been out and i showed up that the alternator wasn't charging.

    But the Halfords testers say it's the battery.

    Will putting a new battery damage it if it is the alternator?

    Atleast then it's a process of elimination
  4. Astramax

    Astramax Super Member

    No, it will not charge and end up drained flat. If the RAC say the alternator is not charging then I would think your existing battery is fine and will continue to be good after being charged up.
    Deleted member 164349 likes this.
  5. Phil the Paver

    Phil the Paver Screwfix Select

    Yes it will ruin a new battery in no time at all, if the alternator is faulty, then it needs changing or repairing.

    How did RAC test it.
  6. Astramax

    Astramax Super Member

    Ruin it or drain it?
  7. Phil the Paver

    Phil the Paver Screwfix Select

    Both possible.
    KIAB likes this.
  8. tore81

    tore81 Screwfix Select

    Local firm tested it with an indicator tool.

    Not sure what the tool was but red light came on saying low battery and alternator.

    Didn't seem a great tester to be honest. Should I trust this and just get the alternator done? What would people do.

    As the battery is gone anyway!

    What I mean if I change the battery and it is the alternator obviously the car will be flat making it clear that it is the alternator.

    I haven't got a lot of knowledge on mechanics.
  9. KIAB

    KIAB Super Member

    Change the alternator, battery will most likely recovered if put on mains battery charger to get fully charged.

    tore81 likes this.
  10. Phil the Paver

    Phil the Paver Screwfix Select

    I posted earlier in this thread how to do a basic alternator test.

    Fully changed battery, engine running, you should have between 13.5 & 15 volts across the battery.
  11. Phil the Paver

    Phil the Paver Screwfix Select

    Good video, but always connect the live first, not the earth.

  12. What car is it on and I see if I can find voltage limits for it.

    Do the test as phil says, but several tests as below

    Engine off, voltage across battery terminals

    Voltage from main connection at back of alternator to battery earth

    Engine running, idle speed, all voltages across battery terminals

    No electrical load, and then with full electrical load, lights, heaters, heated windows etc, but test it in stages to see if anything takes excess current.

    Keep electrics on and increase revs to a steady approx 2500 rpm and test, turning all items off 1 by 1 to check excess again.

    Then finally check voltage at 2500 with no electrical load.

    All figures with engine running should be as phil says between 13.5 and 14.6/7.

    Then turn engine off and take voltage after 60 seconds, then let it stand for 1 hour and read again. Should stabilse between 12.4 to 12.6, the higher the better.
    Phil the Paver and KIAB like this.
  13. Bob Rathbone

    Bob Rathbone Screwfix Select

    Jump start the engine and measure the voltage at the battery terminals after a 5 min idle. It should be around 14 volts. If the battery voltage is lower than 13 volts and the alternator light is glowing, then it's the alternator that is faulty.
  14. Bob Rathbone

    Bob Rathbone Screwfix Select

    Negative and positive on a 2 wire DC system.
  15. WillyEckerslike

    WillyEckerslike Screwfix Select

    I'm sure it's good advice Bob but I doubt they are still waiting for a solution to this after 13 months.
  16. BillyBobToo

    BillyBobToo Active Member

    Congratulations on dragging up a thread that was last dragged up 3½ years ago.

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