Testing the alternator?
  • driver3
    Posts:46
    Joined:Tue Jun 21, 2011 11:45 am
    Testing the alternator?

    by driver3 » Mon Jun 26, 2017 1:37 pm

    Looking for advice on testing the output of my bike - I don't think it's charging effectively.

    I have ruined 2 earthx batteries and 1 shorai. I don't think the bike is charging the batteries. Earthx replaced my battery twice and I'm sitting here with a brand new one in the box - but afraid to put it in until I figure this out.

    If I ride for a few hours, bike turns over fine, etc. Put it on a tender and then it will start fine the next time. If I do a multi-day trip away from the tender.. it's dead mid way through day 2. Kick start only...

    How can I pinpoint this - If it is the stator, I would like to get that out and send to rickystator for a rewind with a higher power setup while I'm at it. But it would be nice to know if it is that or something else...

    thanks in advance!
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    JimDirt
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    Re: Testing the alternator?

    by JimDirt » Mon Jun 26, 2017 9:21 pm

    If its charging you can use a Voltage/Continuity Tester and set it to 20v and see if its above 12.5 at the battery terminals while running (unfortunately you have to connect the battery to test this), it should be around 13-14.5v if its charging correctly , it will raise when you rev it slightly , so the voltage should climb as the RPM's do , then go from there with testing , but that should tell you if the stator is putting out correct voltage

    I can post images from the Factory Service Manual for checking each component if needed , it would be easier than me trying to type it all out , it will just take me a little time to post it as i have to upload each picture to a image hosing site and then paste them here , so it would be best if you can narrow down the source so we can focus on those pages
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • driver3
    Posts:46
    Joined:Tue Jun 21, 2011 11:45 am

    Re: Testing the alternator?

    by driver3 » Tue Jun 27, 2017 6:37 am

    Started it up, didn't wait for warm up, but it goes to 14 when revved. So maybe it is just that my bike hates lithium.

    I bought a lead acid battery and will try that next.
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    JimDirt
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    Re: Testing the alternator?

    by JimDirt » Tue Jun 27, 2017 6:23 pm

    I use a Shorai in my 06 450X and have had it in there since 2011 with no issues and has never needed to be charged.... if its charging correctly , you need to make sure you dont have a direct short somewhere , or a bad ground (the ground connection is just behind the clutch actuator on the ignition side of the case) , leave the voltage meter connected to the battery after the bike shuts down , for 15-30 minutes and see how far the voltage drops , it should never go below 12.5 , and should most likely be around 12.75-13.5 while sitting there , if it drops lower than that then something is draining the battery (tail light ,bare wire rubbing on chassis , etc) , if the battery (LI) is good , there is no reason for it not to hold a charge sitting for months on end , , now if while riding , if you constantly are stopping every mile or so and shutting it off , it would not have enough run time to sufficiently charge it in between startups ...
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho
  • Aussiecrf230
    Posts:1964
    Joined:Fri Jan 06, 2006 11:11 pm

    Re: Testing the alternator?

    by Aussiecrf230 » Wed Jun 28, 2017 4:41 am

    Strange thing about measuring voltage to determine if your alternator is charging is it doesn't take into account there maybe little current flow to charge the battery. Easiest way is put a load across the battery, say a 60 watt headlamp. If you have a 60 watt headlight, it will do the same job. Measuring the voltage across the battery with or without a load will help determine if it is supplying current to charge. The voltage should only drop a little when loaded and certainly not below 13.5 volts at running speed. As Jim has said if there is a bad connection between the alternator to battery (or a bad connection at charge fuse) insufficent current may flow. If you can rig a voltmeter onto the bars you can see if continues charging whilst riding or drops out when things heat up. Give your battery a good charge and then go have it tested to rule it out if only for piece of mind. If it starts ok with a charged battery and then goes flat whilst riding to the point of having to kick start it can't be charging. You don't have massive headlights do you?
    Ray
    Australia

    CRF230F 2004
    C30F Power Up needle
    Mains 132
    Idle 45
    2 turns out
    Baffle out, Screens In

    It starts,it runs,it gets to where all CRFs can get to without the valve or valve plate dramas
  • driver3
    Posts:46
    Joined:Tue Jun 21, 2011 11:45 am

    Re: Testing the alternator?

    by driver3 » Wed Jun 28, 2017 9:46 am

    No massive headlight. I have the trailtech x2, basic bulb light. I can do some spot searches on the wires and see what I find. With the new battery, the bike starts right up, fast spinning starter, etc. I have it on a tender right now. I'll try and take it out this weekend and test it out.

    Last weekend - Rode 120 miles, battery was starting for the first half. Slow starting after. Sat for a day, then wouldn't e-start, not enough juice. Kickstarted and ran with the headlight off for 60 miles, no stopping. Still no charge. Got home after the next 60, no starting, no charge. Kick start of course works fine : ) For what it's worth, the shorai shows 13.4 V on the bike.. when I hit the start it drops to 3 or 4V.

    1 Shorai, 2 earth-x batteries. All have failed. At least I paid only $26 for this new battery on amazon.
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    JimDirt
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    Re: Testing the alternator?

    by JimDirt » Wed Jun 28, 2017 12:38 pm

    Well if its dropping to 3-4v , then the battery is toast , the issue is , did the batteries go bad on their own ?? , or is something shorting out or drawing juice that is killing them ?? , that is what you need to test for now , start eliminating items 1 by 1 , right down to unhooking the trail tech light system completely by the end of testing , this will individually eliminate each connection in the system , and should narrow the results to 1 or more items causing the drain , though its possible to have 3 different brand batteries go bad , i find it highly unlikely and suspect that something is killing them by a short or poor connection or bad component , if after the ride this battery also dies or gets low , then testing by elimination of the Trail Tech system is your best bet to locate the source of the drain...

    Start by removing the bulb itself , then ride , so on and so on
    2020 CRF450R
    2006 CRF450X
    Image
    Weiser , Idaho

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