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CBR250RR battery going dead quickly

Discussion in 'Bling and Appearance' started by davidgock, May 10, 2008.

  1. Hi guys,

    I just bought a CBR250RR and it seems that the battery goes flat after 4-5 days. I thought that maybe this is a common problem (maybe a wire is poorly placed and frays easily, causing a short circuit) or something? THe bike has the 60W headlight mod and ShiftR lights.


  2. Welcome to the wonderful world of Honda electrics.

    It's almost certain that the voltage regulator has gone to God, meaning the battery is not getting a good charge when the bike is running. See you local mechanic and get it checked and/or replaced. Depending on how long this has been going on, you may find you may have to replace the battery as well.
  3. It might not be that serious. Maybe the battery is buggered. Easily checked with a multimeter.
  4. Get a voltmeter.

    Check the battery voltage when the bike is not on... It should read between 11-12.5.

    Check the battery voltage when the bike is turned on and running. Rev the engine to about 4k. It should read around 14.5 <--- if no then your altenator.

    Good luck.
  5. No, it's HIGHLY unlikely to be the alternator, but VERY likely to be the voltage regulator....
  6. I put my money on regulator....

    Had a very similar experence when my regulator died and burnt the wires connected to it :shock: After the wires were fried my bike started acting funny, like if I turned on the highbeam the engine would die.... Before it acted really funny. My bike had exectly the same problem as u described.

    Luckily my battery was ok..
  7. Thanks for the quick feedback fellas. I don't think that it's the alternator because I've been riding around on it for a while with the lights on, etc.

    I have tested the voltage without the engine running and it's 12V; will test again tonight with it running.

    Is there a way to test the voltage regulator? I'm a DIY kind of guy (poor).
  8. Test the voltage with the engine running. it should be around 13.5-14.5V and should be steady.
  9. Cheers mate.

    If it's buggered, where can I get a new (working) one?
  10. You might also need to test for current and not just voltage. My bike suffered a burned out rec/reg which took the battery with it - turned out that the rec/reg didn't have a metal backing plate to transfer heat to.

    The thing was, for my bike, that the voltage continued to be fine, but there was bugger all current flowing through the electrics. However, measuring current requires that you do it properly, otherwise you could do some damage. Unfortunately I don't know how.

    Yeah, Honda still make them I think. At least, I am pretty sure they put a new OEM one on my bike.
  11. if ur battery is screwed dont go riding around on it, it will overload ur alternator and blow ur doube lacke (COMPLETE MIND BLANK) but i know its important