Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Battery is charged while riding or idle?

Discussion in 'Technical and Troubleshooting Torque' started by evo6, Apr 24, 2006.

  1. hey boys and gals,

    Question as title, I found my CBR250rr manual, it said the battery get charged if rpm less than 1900, it means the bike is idle.

    But i heard another statement before, that is the battery get charged while riding more than 6000rpm.

    Which one is true to CBR250rr? Pls advise.
  2. I thought it was above 2000RPM, less is definately not better.
    Could be as high as 6000, but i highly doubt it.
  3. I've seen that before too, I just assumed it charges at 1900rpm with the headlights and other electrics off but more revs are needed to charge the battery if these things are on.

    just a guess
  4. AFAIK, once the engine is going the battery is receiving some degree of charge from the alternator (which is converts mechanical power into electricity). The amount of alternator voltage required to increase battery charge would be dependant on headlights and other appliances. on a cbr250, you could pretty much assume that with the headlight off it would charge at idle, although I'll stand corrected.

    It will definitely charge better with higher rpms and longer periods. Perhaps invest in a trickle charger?
  5. I see. so the manual i read may not refer to the CBR250 in Australia. Since there is no way to switch off the headlight.

    But the manual did say less than 1900rpm with headlight at low beam. I don't get it, it is LESS THAN.

    anyone got the hard copy of the manual for Aus Model? Take a look at it, see what is in there? (since my manual is downloaded from internet, and may just for Jap Model).
  6. Look at the red light (Charge light) on your dash. If it is dark, it is charging. (Cannot tell how much, but it is charging).

    If light is glowing a small amount the charge is slight. If the light is bright, it is not charging.

    When you switch the ignition switch to on, the light should be bright. Once the engine is running, the light should change to a less bright glow. If it is glowing slightly, slowly raise the revs slowly until it goes out. That is the rev that is needed to charge. Each bike can be different depending on light globe loads and charging system things like brushes, comutator etc etc.

    Sometimes a quick blip will get it charging and then it might charge on the idle.

    Try it and find out.
  7. my battery went flat on cbx today ( left headlight on and keys in while i messed with car ) but on way home as revs were above 2000rpm charge remained higher and constant, so above 2000rpm, when i put headlight on it dropped of a lot more at 1400rpm than above 2000 :) (volts that is)
  8. It's not easy to say as there may be a gearing difference between your alternator and your engine revs.

    Generally manufacturers will set up an alternator so it is not quite or only just charging at idle.

    alternators are better then generators in this respect as thy don't kick in untill around 3000 rpm.

    If the light is out on the dashboard then it is recieving some charge but it may be more then the drain on the battery, so don't take it as an absolute.
  9. the 6000 is usually peak output engine speed.

    OP, use a meter on the battery terminals when the bike is running to find out - look for voltage of ~12.8-13.low for neutral, higher for good charging, lower for no charging at all.
  10. charging

    Most alternators today work at idling speed,depends on construction of the alternator,but pretty much every alternator in cars or bikes nowdays is charging at idle,the charge current depends on how many poles in the alternators stator it has,the stator is steel and iron laminations,squished together,the more poles(nth-sth magnets with bits of chunky wire wrapped around them)the better the charge.Obviously as said the more revs,the more its charging.If at idle as mentioned,and lights on,then you rev it and it gets brighter,its charging,exactly same in your car,turn on interior light with the motor of,then start it,if your light doesnt get brighter,chances are youre alternator aint doing what it paid for-perhaps it has a new workplace agreement under Johnny Howard and is on strike. :roll: