Draining battery problem

Discussion in 'Electrical' started by Mr.Mathews, Jun 5, 2018.

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  1. Jun 5, 2018 #1

    Mr.Mathews

    Mr.Mathews

    Mr.Mathews

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    Hello all,
    I am having an issue where something seems to be killing my battery while my 85 vmax is off. It also seems to not be charging while running. My initial guess is the R/R for the charging issue. Haven't had time to go through the test chart and verify it. But just looking to see if there are any recommendations on where to start looking for what's draining my battery while the bike is off. The battery is new btw.

    Thank you in advance for any advice.
     
  2. Jun 5, 2018 #2

    mabdcmb@yahoo.com

    mabdcmb@yahoo.com

    mabdcmb@yahoo.com

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    Grab a multi meter that capable of measuring DC Current (milliamps/amps)

    Remove negative terminal from battery. Connect it to one of the multi meter leads. Connect other multi meter lead to battery. Your meter is basically completing the circuit.

    Put meter on DC Amps. Reading should be in the very low milliamps.

    Pull one fuse at a time to to isolate the circuit thats draining. Once you figure out which circuit you can disconnect individual components till you find the problem

    Sent from my SM-G930V using Tapatalk
     
    Last edited: Jun 6, 2018
  3. Jun 6, 2018 #3

    sdt354

    sdt354

    sdt354

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    The R/R can drain the battery while not running. Unplug the R/R red wire connector with the multimeter connected to isolate it like you did the fuses.
     
  4. Jun 6, 2018 #4

    Bill Seward

    Bill Seward

    Bill Seward

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    If it turns out you have a R/R problem, read up on the MOSFET regulator upgrade. Inexpensive, simple, and makes a great difference in the way the early Maxes charge. Consider finding a SH775 Series regulator. Exact same plugs and dimensions, same procedure to do the mod. The Series regulator is much easier on the stator, as it doesn't shunt excess current to ground through the stator coils. This prolongs their life. I've got a Series unit in my '85, wired directly to battery. I get over 14 volts at 1500 rpm. The unit doesn't get hot, so you can pretty much put it anywhere. Mine lives under the seat, where the rear cylinder coils used to be.
     

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