Boiling battery woes

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by Deepc, Mar 7, 2013.

  1. Deepc

    Deepc Been here awhile

    Apr 11, 2011
    St. Petersburg, Florida
    2005.5 950A w/20,0000 miles. I recently replaced my balancer shaft seal. This involved disconnecting the generator plug and removing the stator cover. My bike ran great for about a month. Two weeks ago, I went to start my bike only to find that my fancy Shorai battery was dead. Upon further inspection the battery had actually melted. I put in another battery, this time a Yuasa, and she began to hiss and boil. I'm guessing that my voltage regulator is shot. What is the best way to test the voltage regulator? Could anything else be causing this issue. Any help would be greatly appreciated. This bike is really starting to wear on me...


  2. It'sNotTheBike

    It'sNotTheBike Banned

    Jul 20, 2011

    I went through the EXACT scenario you describe above with
    my KTM 950 Super Enduro. But it's easy to fix and the fix
    will be much more reliable than the OEM regulator assuming you
    take my advice and buy the best regulator available, as detailed
    below. Don't be too pissed at the bike, it's not a huge expense to fix
    properly and it takes maybe an hour at most to do the installation
    of the new regulator. After you install the new part the bike WILL be
    more reliable than it was from the factory.

    I don't think you "need" to test the voltage regulator. It has
    already destroyed one battery and perhaps the second battery also.
    It's pretty obvious the regulator has failed and you need a new one.

    But if you insist, here is how to check the voltage regulator :

    1) set your voltmeter to DC volts and set the meter range to 20 volts
    or whichever meter setting is not less than 20 volts but closest to the 20
    volt range.

    2) Connect the positive test lead from your meter to the positive
    pole of the battery which is connected to the bike's wiring harness.

    3) Connect the negative test lead from the meter to the negative pole
    of the bike's battery.

    4) start the engine of the bike and watch the meter as you rev the
    engine up to at least 3,000 RPM. You will probably see voltage in excess
    of 16 volts. Any voltage in excess of 14.5 volts means the regulator is
    malfunctioning. Don't run the bike any longer than necessary to perform
    the test because overcharging will damage the battery. A Shorai will be
    destroyed much quicker than a lead-acid Yuasa battery but any battery
    will be destroyed by overcharging.

    It is ESSENTIAL you make certain all the wiring which is related to
    the battery and charging system is in good condition and is connected
    as it should be. If some ground wires are left disconnected damage
    can result. The failure in your bike is probably unrelated to the recent work
    you did but you do need to make sure the wiring is in correct order.


    Now, how to fix it.

    You need a new voltage regulator. I suggest you avoid
    buying one from Rick's Motorsport Electrics because the
    regulator sold by that business is poor quality and there are
    better regulators available from different sources for the same

    The regulator you want is the Shindengen brand, which uses MOSFET
    circuitry which means it produces dramatically less waste heat
    during operation and is less likely to fail because of this circuitry.

    The supplier I prefer to deal with is this one :

    Roadster Cycle is owned and run by one man, whose first name
    is Jack. He is extremely helpful and very knowledgeable and the
    kits he sells are quite nice and much better quality than the stuff
    sold by Rick's. If anyone tells you that Rick's sells top quality stuff they
    don't know what they are talking about and if you take their advice
    and buy that Rick's stuff you have only yourself to blame.

    You need to perform tests to verify whether the rest of
    your charging system is operating correctly, BEFORE you
    install a new regulator/rectifier. This includes testing the battery.
    You should charge the battery using a charger which is known
    to be working properly and check the battery after charging to
    see if it has been damaged or not.

    You can find the info on how to check the rest of your bike's charging
    system in the web page below. It is easy to check everything and takes
    maybe 20 minutes at most. All you need to perform the tests is an electrical
    multimeter which can work in AC volts, DC volts, and Ohms. Shop/Troubleshooting Charging Systems/charging_systems.html

  3. Deepc

    Deepc Been here awhile

    Apr 11, 2011
    St. Petersburg, Florida

    This is a amazing reply. Thanks for all of your information. I don't think I could handle this bike without help from people like you.
  4. It'sNotTheBike

    It'sNotTheBike Banned

    Jul 20, 2011

    You're welcome.

    I had to figure some of this stuff out myself when it happened
    to me, but there's no point in you suffering as much as I did :D

    If you methodically do all the tests and order a good regulator
    and do the install carefully, the bike should be just fine. You may need
    to buy yet another battery -- if the Yuasa is damaged it can damage the
    new regulator if you try to run the bike with it. Best to start with a battery
    which is 100% known good and be careful and do everything properly the
    first time and the results will be what you want.

  5. pdxmotorhead

    pdxmotorhead Long timer

    Mar 4, 2012
    Portland OR
    If you have a battery specialty place like batteries-plus they can test the battery for you before you try it..

  6. Deepc

    Deepc Been here awhile

    Apr 11, 2011
    St. Petersburg, Florida
    Thanks. I'll definitely check the Yuasa at a reputable battery store. The saving grace was that all of this happened less than 5 miles from home.