1. Dismiss Notice
  2. Hey Facebook people... We've created a group for XS650.com members to connect. Check it out!
    Dismiss Notice

Overcharging issues that just won't quit!

Discussion in 'The Garage' started by Naturalsystem, Sep 11, 2020.

  1. Ok, a little update!
    I got the rectifier and regulator, mounted them on a plate to go where the original combined unit would mount and the bike fired up first kick with ease.
    sitting around 13.6v at a bit higher than idle... (sorry I have no tach haha) but I'm confident that it is fixed.

    I'm still seeing about 1.5V less than battery voltage on the positive brush when Key On, I've read conflicting things about this though.
    Some say that close to battery voltage is acceptable, other's (including curly's guide) say that battery voltage needs to be present.
    I have cleaned up the wiring AGAIN, beefed up all the grounds and power cables as well.
    I can't quite put my finger on it - any suggestions?

    I also have a question about finding a new battery.
    When looking, I'm seeing a lot of batteries in the footprint I want, but the max charge is usually 1.8amps.
    Is this an issue?
    Any suggestions on a small AGM battery?
  2. 650Skull

    650Skull SSSSSSSSSlither Top Contributor

    Well that's top news......

    Checked each side of the ignition switch.........

    Battery.....someone else can comment..........
    gggGary and Naturalsystem like this.
  3. gggGary

    gggGary Stop that! XS650.com Supporter Top Contributor

    Yes if you haven't yet a iggy switch overhaul is nearly always a good idea, but slightly lower volts at the hot brush is normal, the wires are thin, the path long and load from the rotor significant. Don't go for bigger wires, the stock wire sizing works just fine if the system is kept maintained.
    TwoManyXS1Bs likes this.
  4. TwoManyXS1Bs

    TwoManyXS1Bs BBQ Hunter Top Contributor

    With solid-state type regulators, rotor current has to flow thru a power transistor. There'll always be some sort of voltage drop across a semiconductor, known as Vf (Forward Voltage drop).

    This pic showing the two types of regulators, shows the power transistors.
    The upper pic, for a type "B", shows current flows from B+, thru the transistor, to the rotor.


    Voltage drop across transistors can be anywhere from 0.6v to 1.5v.
    This, plus any wiring/connector/switch resistances, will add up to give you the voltage drop you're reading.

    The OEM regulator is a relay type, no voltage drop across its contacts...
    gggGary, Rasputin and Naturalsystem like this.
  5. That is EXACTLY the explanation I've been looking for. Thank you for that.
    I really should've known better but I let internet/forum knowledge get the better of me haha
    TwoManyXS1Bs likes this.

Share This Page