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Stop start battery failure cause?

Discussion in 'LR4' started by Fuji4, Nov 25, 2019.

  1. Fuji4

    Fuji4 Full Access Member

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    Now keeping in mind that I have disabled the stop start feature permanently I find it odd that the stop start battery is totally dead. It was replaced at 45k miles or so by the dealer. I was thinking about using the aux battery to power my BlackVue dash cam in parking mode but then found out it is totally dead.
    Now do we have a reason why it’s (and everyone else’s) dead? Does it not charge properly from the alternator? Or do they die from use or age?
    Because I can replace it and then use it as a dash cam battery but if it doesn’t charge properly that will be pointless.
    Any thoughts ?
     
  2. ClevelandLR4

    ClevelandLR4 Member

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    Can you check if current flows to aux battery from alternator when vehicle is ideling?
    Was it a software fix or hard wire disconnect fix for permanent removal of stop start function?
     
  3. Fuji4

    Fuji4 Full Access Member

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    It was a software fix. I tuned it with velocity AP and they shut it off as an option with a flasher. I’ll have to dig into the dead battery this weekend. I just left it alone after installing the dash cam setup. But it is mighty dead. Of course that is also a great solution to the start stop annoyance.
     
  4. Waterndirt

    Waterndirt Full Access Member

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    So after the software fix / flash, did you have an Amber Eco (Unavailable) Dash light on all the time? This is the first confirmation, that I know of, that software can turn the ECO system off.
     
  5. Fuji4

    Fuji4 Full Access Member

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    Yes. The eco light stays on.
     
  6. Robuk

    Robuk Active Member

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    To test whether aux is being charged uncover aux battery, start the car, connect the probes of a multimeter to battery terminals, ensure meter is set to DC, you should see a reading around 14 volts. If it is less than 12 volts it`s not being charged.
     
  7. ClevelandLR4

    ClevelandLR4 Member

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    Any updates fuji4?
     
  8. Fuji4

    Fuji4 Full Access Member

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    Not yet. I had to get a new main battery yesterday and have not had a chance to get the multi meter in the aux one. I’ll try and do that today.
    On another note when putting in the H7 I realized that I had an H8 in there previously. I know I replaced it in 2014 but don’t think I did anything to the BMS via the IID tool. I am also going to pull the BMS off the negative terminal per Robucks advice.
     
  9. avslash

    avslash Full Access Member

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    If it works for you without getting "Charging System Fault" on the display, let me know. I was never able to avoid the fault with any combination of sensor/IIDTool settings.
     
  10. Fuji4

    Fuji4 Full Access Member

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    Ok here is the multimeter results. 6509E7DC-42BE-4BE0-8D3B-3F20BCA30606.jpeg 06A6970B-43BD-4F80-BEA6-2E971BE0E041.jpeg
    Nothing to the aux battery.
     

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