fbpx
Login

 

Jump to Forum..

912UL Voltage High

in General Tech Discussion 7 years ago
I have a 2007 912UL engine. Voltage seems to be running higher than usual. Have EIS to alarm at 14.3 volts and it has been hitting 14.4 volts on a regular basis lately setting off the red blinking light. Ambient temperatures are high here in Fresno, CA in excess of 100F

What is an acceptable max voltage and if 14.4 is too high how is it lowered?

William Campbell

  • Re: 912UL Voltage High

    by » 7 years ago

    What regulator/rectifier are you using? Ducati? John Deere?
      
    Report

  • Re: 912UL Voltage High

    by » 7 years ago

    If you bump 14.4 occasionally it isn't a problem.. If it goes higher and stays higher then you need to take a look. Out of curiosity, What kind of condition is your main battery in and do you have the required capacitor installed and is it in working condition?

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

      
    Report

  • Re: 912UL Voltage High

    by » 7 years ago

    I just checked on when I bought the battery and it is over 3 years old. So we will replace that right away. Also my partner is going to check to see if the capacitor may be leaking. I will get back to you after we replace the battery and check the capacitor.

    Thanks for your input - greatly appreciated.

    Bill
      
    Report

  • Re: 912UL Voltage High

    by » 7 years ago

    Before you blindly replace the battery...

    Disable the ignition.
    Crank the starter for 30 seconds. (Actually time it!)
    Wait 5 minutes for things to cool.
    Crank it again for another 30 seconds.
    If it is still cranking, the battery is good!

    14.4 is nothing to get concerned about.
    It could be the high temperatures.
    Don't overlook the measurement side of the equation.
    Your 14.2v regulator could be creeping up to 14.3 in the heat.
    And the EIS could be over reporting the 14.3 as 14.4 because it is also affected by the heat.
    Put a quality Voltmeter on the battery to confirm the actual voltage.

    Wet Lead Acid batteries can handle 15v all day
    AGM Batteries should be limited to 14.7v
    Gel Batteries should be limited to 14.5v

    Your Electronics can typically handle at least 18v minimum.
    Nothing should be designed that can't take at least 16v.
    Most avionics are dual voltage and are good for anything from 10 to 30v.
    They can be installed in a 12v or 24v plane.

    Test the battery before you spend money needlessly.

    Bill Hertzel
    Rotax 912is
    North Ridgeville, OH, USA
    Clicking the "Thank You" is Always Appreciated by Everyone.

    Thank you said by: William Campbell
      
    Report

  • Re: 912UL Voltage High

    by » 7 years ago

    I agree with Bill. I didn't mean to imply that you should change the battery or even that it as bad. Just was curious during your trouble shooting if you had checked on these things.
    Sorry if I implied to swap the battery.

    Roger Lee
    LSRM-A & Rotax Instructor & Rotax IRC
    Tucson, AZ Ryan Airfield (KRYN)
    520-349-7056 Cell

      
    Report
You do not have permissions to reply to this topic.
Related Topics
Title Category Replies
Seeking Advice on MAP and RPM Limits for Rotax 912ULS (Post-SB-912-079) 912 / 914 Technical Questions 2
912ULS Exhaust Spring Tension 912 / 914 Technical Questions 6
RPM Drop in 912ULS 912 / 914 Technical Questions 3
RPM Drop in 912ULS 912 / 914 Technical Questions 21
Rv-12iS High EGT and Coolant temps 912iS Technical Questions 3
Follow Us

Recent Videos

Safety First!

 

To receive critical-to-safety information on your ROTAX Engine, please subscribe to
ROTAX-OWNER.COM

Prize Giveaway!


SUBSCRIBE NOW
to automatically enter this years draw!

Login