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the Battery Killer

Discussion in 'Motorcycle Tech Talk' started by Hogdog, Oct 29, 2017.

  1. Hogdog

    Hogdog Active Member

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    Hello,

    I have a HD 2008 Ultra Classic that is killing batteries. Battery as measured at terminals is 12 v. Voltmeter on bike reads 10v (?) Now when I start here up its sluggish but starts thankfully on the first turn. Run her for about 10 minutes kill her and try to start again. Even more sluggish but starts first turn. Bike V meter reads 10 v. KIl her and try again...she is dead. Is it unreasonable to expect this years model to start 3 times in a row. Battery is 2 1/2 year old. Best thing I can come up with is the draw on the battery exceeds what battery can deliver. what should the current draw be for starting this bike?

    Thanks in advance for your interest
  2. Red Rider

    Red Rider Well-Known Member

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    It sounds to me as if your bike has a wiring short - I had similar symptoms a few years back. We found that wires running along the frame had been worn just enough to ground and /or arc to the frame - but not constantly. Check your wire harness everywhere you can, paying special attention to places where it is tight against the frame or can be pinched. Look for indications of minor scorching, too. If you can, check it over (preferably on a lift) while it is running - shut the lights off (or make it dark around the bike anyway ya can) and give it a a thorough look. That is how we found my bike's problem, heard the "ticking" where the wires disappeared near the oil filter while running it, and then shut the lights off and saw the tiny flashes from the sparking.

    Of course, my "diagnosis" is only a valid one if you know your battery is good. Do you KNOW that? Some just suck from the get-go, try a swap with a buddy if you can.
  3. charlie46

    charlie46 Well-Known Member

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    Try disconnecting your battery and hooking volt meter between disconnected cable and it's battery post. With key off should be zero. If it's zero trouble with battery or starting circuit. If it's not zero you've got a short somewhere like RR said.
  4. Hogdog

    Hogdog Active Member

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    Isn't there a constant draw on the battery for all the electronics (example clock?). If not this is a good idea. Thanks charlie46 for your interest and suggestion.
  5. Hogdog

    Hogdog Active Member

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    Thanks Red Rider,

    This is the 2nd battery in about 4 years, the current battery is about 2 years old. Of course it can be at fault, except this is the second battery in 4 years and the first was declared dead in a similar way. The battery in my 89 ultra still is strong after 20 years so I suspect something in the bike as you have pointed out.

    Thanks for your suggestion and interest
  6. hotroadking

    hotroadking Super Moderator Staff Member

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    If you have a 20 year old battery on a Harley that still works they'd like you to send it in for the Museum LOL.

    Batteries today last about 2 to 4 years, I'd suggest you get a battery tender for the
    bike and hook it up when you are not riding, there are draws for the newer bikes, radios, alarms, ECM, etc, we're lucky to get 4 years from a battery here in FL the heat combined with the above, I run a battery tender.

    Link to Battery Tender


    They have several models, they are designed to smart charge better than a trickle charger, it watches the battery, it's charge level and turns on an off the new batteries are AGM, a little different than the old lead acid batteries.

    And sometimes a battery just goes bad, plate breaks off internally, cell goes
    dead, it just happens. You don't have to give HD your hard earned green for a new
    battery, Autozone has them for significantly less

    https://shop.advanceautoparts.com/p...-powersport-battery-385-cca-tx30la/16940019-P
  7. charlie46

    charlie46 Well-Known Member

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    Online; Battery Mart. Good deals,free shipping. ps battery after 3 yrs in Fl. it's a crap shoot every time you start.
  8. Red Rider

    Red Rider Well-Known Member

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    Hogdog - I forgot to ask if you have the H-D security system, and if you do are you keeping it on a battery tender? That system is crap and a real battery drain.
  9. Hogdog

    Hogdog Active Member

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    Thanks Red Rider for the tip,

    One nice morning, a perfect riding day was shot to h**l because of a stupid button battery in the fobb. That piece of crap was disabled shortly thereafter. I believe the security is still active just fobbless. I keep all my bikes on battery tenders never have any battery trouble with the FXDWG or the 89 ultra.
  10. Hogdog

    Hogdog Active Member

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    We riders stick together thanks everyone for tips and suggestions,

    I got away easy on this one. Disconnected battery to do the current draw test, it was as expected. Cleaned and polished (little bit of tobacco juice) the battery terminals. Problem disappeared. Lesson learned on hard start, clean battery terminals (use tobacco juice) and check ground connections
    Red Rider likes this.
  11. hotroadking

    hotroadking Super Moderator Staff Member

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    good for you...

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