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Hello Experts,
My 6 month old battery seems to run down within 2 weeks and maybe is not charging. I charged it up and could take a load well. Then 2 weeks later, it ran down again and I had to pop the clutch a few times to get started again. Could it be the starter relay, voltage regulator or the alternator? The battery tests good.
Thank you.
Brian in VA
 

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How OLD is the battery ?

You NEED a voltmeter to check the charging voltage.

Then......if you only ride it every 2 weeks, you might need a battery "tender" charger to keep the battery from going bad, even if everything is working right.
 

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What Nick says...you should see at least 13.5 vdc across the battery with the motor running ... most newer bikes now put that out even at idle. At rest your battery should read around 12.5 vdc...any less can point to a parasitic draw, it needing charging or the battery being toast. off the bike it should read 12.5 vdc fully charged and should retain that for a good while with no major drop....two weeks at least. When cranking the voltage must not drop lower than 10 vdc...if it does it probably means the battery is toast.

Good luck
 

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14.5 volts at 4k rpm is what your charging system should be doing with a good battery. What brand battery are you using? Have you checked your stator connector for corrosion? Usually a good battery that slowly dies with riding is a sign of a weak stator or failing reg/rec.
 

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Battery voltage will bleed down due to internal resistance leakages over a couple weeks. If you have anything like an alarm system or aftermarket radio that has a memory circuit, those will bleed down the battery over time, too. I'd check with any previous owner installed equipment (lights, etc.) to see if it was properly wired. (Turning off key should shut all power except for alarm and radio memory circuits.)

I'd get a battery tender. One of those that charges at 0.5 to 1 amp then goes into trickle maintainer mode (shuts off when charged, then on and off periodically to keep battery topped off) are good.
 

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Two things you can do right off. First, check the connector for the stator, they have a bad habit of burning up. Before you buy expensive charging system parts, drain the oil and take the stator cover off. If you find the magnets are caked with metallic goo, clean it all off thoroughly and put it back together. Eliminate the connector (3 big yellow wires) and solder them to the bikes harness. This will fix most charging problems as long as the rectifier isn’t burned out
 
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