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Battery problems

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Tyberious Funk, Feb 28, 2009.

  1. I went out for a ride this morning, only to find my bike wouldn't start. Completely, utterly dead. No lights, no horn, nothing turning over... zip, nadda.

    I managed to get a jump start, but it was pretty droopy... horn sounded like a wet fart, indicators struggled and the headlight was very weak. After 20 minutes of running, I turned the engine off, and tried to start it again without the jumpers. Again, I got nothing. Even the neutral light wouldn't switch on.

    To a n00b like myself, it seems like the battery isn't holding a charge and probably needs to be replaced.

    Or am I doing something wrong?

    And if I do need a new battery, where am I going to get one on a Sunday in Melbourne??
  2. Probably battery, if the bike runs once started and you have headlight etc then charge circuit is probably Ok. Not sure about buying a battery on Sunday you will have to ring around.

    Maybe: http://www.batteryworld.com.au
  3. charging!

    A dud battery can cause all sorts of havoc

    Couple of things, if the bike has been sitting for a while then completely normal. If the bike has been used regularly, then points to issues with your 'reg' or regulator (diode array that regulates voltage feed into battery). You can test out the 'reg' issue with a multi-meter.

    At idle the charge generated by the motor/reg is low, not enough to charge the battery over 20 mins. Suggest you a) connect a charger b) give the bike a run at decent revs (4000+) for a period greater than 20 mins and see what happens.

    Constantly letting the battery get flat (e.g. sitting for a week) will degrade the battery far quicker than normal. If this is common place then get a 'trickle charger' ($40-70) to top things up when necessary.


    P.S. if you want at battery consider Gassit in Fairfield.
  4. If you need a battery, Stupidcheap sell the most popular ones, don't forget to buy the acid with it, they are dry charged.
  5. Let's assume the bike's a Honda, shall we?

    Replace the regulator and the battery.

  6. Before you spent cash I hope you disconnected the battery leads and cleaned them and the terminals and re attached them.
    Then check the voltage with a $10 multi-metre.

    EDIT: Oops wrong meter :oops:
  7. Oh yes, second that, check the basics first!

  8. CBR250RR


    I also had an issue with a bike that wouldnt start,

    New battery 5 weeks ago,
    Holiday for 3 weeks (bike not started)
    Upon arriving home, it was started and idled for only 10-20mins
    2 weeks later of sitting, attempted to start it and it wouldnt.
    Jump starting it down the street in 2nd gear got it going.

    Applied mutlimeter to it and came up 12.53 (this is after jumpstarting and taking for a 30min run)

    Bought a CTEK XS3600 charger which includes a slight desulphation mode and it took 3hours to move from charge mode to full charged.

    Applied multimeter and came up 12.93.

    Next morning, it started by itself, but I did not ride it just turned it off again.
    Later in the day I applied the multimeter to it and it came up 12.50, thought i would reconnect the CTEK and expected it to be in the FULLY charged mode, but went into charging mode again.

    Only took 1hour this time to return to Fully charged. Measured batt voltage after disconnecting charger and it was 12.9. Turned bike on and measured voltage across terminals and its 12.53.

    What should a healthy battery voltage be when not running?

    What Voltage should the alternator be charging at? 12.5 seems low as for cars a reading of 14.4V normally indicates a healthy alternator?

    How do you test the regulator with the multimeter?

    I will now leave it for a week until Sat or Sun and see if it starts itself.
  9. Re: CBR250RR

    It's pretty simple (though I'd defer to my mechanic brother for the specific steps).

    Here goes, get a multimeter (set to measure voltage) and have the bike running. Apply one lead to frame (bare metal), one to a battery terminal (whichever one).

    Observe the voltage level and importantly bring the BIKEs REVS UP. At idle you'l get 11 or 12 volts, but at higher revs (like when you are riding the bike) the voltage generated will come up (to say 14 or 16v or whatever).

    If you are revving the bike hard(er)/high/lots etc but your voltage is not coming up from 11-12v then the source of the problem MAY be a dodgy regulator (they do wear out.

    Depending on which lead goes where the voltage flow will be + or -, that does not matter, the level of voltage detected counts.

    Another way to spot a dodgy reg is when at idle you lights (headlights etc) pulse brighter-darker-brighter-darker as the bike ticks over. One of the diodes (one way flow electronics) in the array that controls flow of voltage may not be functioning correctly.

    Hope this helps!
  10. Is there an actual ideal figure for motorbike alternators like cars its 14.4V when you apply the multimeter.

    That figure is also one at idle.

    Also, what should the battery be when tested at any given time (engine off).

  11. A mildly educated response here, so don't hold it against me :)

    - Ideal figure is dependent on RPM, so at idle close to 12v at revs closer to 14v (this is also influenced by a number of other factors).

    - When off you would expect the battery to have close to 12v of charge.

    - Note that it's the current (different to voltage) a battery holds that turns the engine over. Checking the voltage a battery holds is just a quick indicator of the battery's condition. Low battery voltage reading (whilst off) points to a flat or damaged battery.
  12. Thanks for some of the suggestions and advice.

    I'll get a multimeter and test things out. I suspect/hope it isn't a problem with the regulator though, just an old battery struggling to hold a charge and a bike not being ridden regularly enough to keep things ticking over.

    This is proving to be a valuable reminder in turning the engine over even when I can't get out for a proper ride.
  13. Thanks for these numbers, they've helped me a lot.

    I took some readings last night. 12v at idle and around 14v with the engine revving. Unconnected, though, the battery was only reading 6v. Given it's a 12v battery, I guess that confirms it is flat. Whether it is damaged or not, is another matter -- at least the problem seems confined to the battery.

    Can anyone recommend a battery charger to buy?
  14. You have one built in if you ride enough :wink:
  15. im an auto elec, and i would say put in a new battery first. if still the same, check the alt and reg, if still the same, check the charge wire from your alt to your battery, check for corroded connections

  16. Wow an 18 year old auto elec???????
  17. Don't be fooled by a reg saying 14.4v on it. This is simply to let you know that the reg is set to not charge over 14.4v, anything over should be considered "excessive charging". A charge voltage of 13.4-14.4v is sufficient.

    But yes it sounds like the battery has become open circuit, check it with a multimeter if it has little or no voltage, replace it.

    I'm a 20yr old auto elec about to finish my trade (I started at 16).
  18. But you are not qualified as yet, when you ARE THEN you can claim to be.