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F2NV
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Discussion Starter · #1 ·
So I was out riding for like 45 minutes. Went to come back home and got to the light about a mile from my house and it shuts itself off.

I tried to start it but the whole electrical was dead. I troubleshot some things - swapped fan and starter relay, checked voltage on starter, tightened the bolts on the battery more than a quarter turn.

I jumped it with a portable jumper and since then it has fired up every time. I haven't been able to put too much time on the saddle but I'm concerned it may do this again.

The battery is almost 3 years old and is always on a tender.

Any thoughts?
 

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So I was out riding for like 45 minutes. Went to come back home and got to the light about a mile from my house and it shuts itself off.

I tried to start it but the whole electrical was dead. I troubleshot some things - swapped fan and starter relay, checked voltage on starter, tightened the bolts on the battery more than a quarter turn.

I jumped it with a portable jumper and since then it has fired up every time. I haven't been able to put too much time on the saddle but I'm concerned it may do this again.

The battery is almost 3 years old and is always on a tender.

Any thoughts?
Since it started with a boost, the battery voltage must have dropped to about 9 volts. The ECM doesn't want to play any more when it hits that low number and bike will quit. Check your charging volts to be with in 13.8-14.2. If that is good, most likely battery is pooched. If not charging, well that's the problem. Battery wise, a cracked plate that can be intermittent with battery current output. If it did it once, it's just a matter of time before it does it again, even though everything seems fine now.
Ron
 

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Tightening battery cables more than a quarter turn sounds like they were kinda loose to me.3yr old battery is not old but things do happen.Do you know a battery shop or parts store that can load test it?Put a meter on it and see how far voltage drops when starting.Should not go below 10,I believe.
 

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F2NV
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Discussion Starter · #6 ·
Thanks yall for the input. I'll put a meter on it next time I start it.

I checked all the fuses and they looked good.

Im starting to think I'm on borrowed time with the battery. Maybe 1-2 years more on it.

If the battery became disconnected while running, should the bike keep running or would it die?
 

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...
...I'll put a meter on it next time I start it.

I checked all the fuses and they looked good.

Im starting to think I'm on borrowed time with the battery. Maybe 1-2 years more on it.

If the battery became disconnected while running, should the bike keep running or would it die?
No, the battery isn't needed once the engine is running but a weak battery with poor connections could cause your issue.

A discharged battery buts a high current demand on the charging system and at idle the VR output could drop below 12 V. This combined with bad battery connections could cause a lot of low (or high) voltage spikes that might cause the engine to die and/or damage the VR. To test the VR, measure the voltage at the battery terminals with the engine running at 3000 RPM. It should measure above 13 V but less than 15.7 V.
 

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No, the battery isn't needed once the engine is running but a weak battery with poor connections could cause your issue.

A discharged battery buts a high current demand on the charging system and at idle the VR output could drop below 12 V. This combined with bad battery connections could cause a lot of low (or high) voltage spikes that might cause the engine to die and/or damage the VR. To test the VR, measure the voltage at the battery terminals with the engine running at 3000 RPM. It should measure above 13 V but less than 15.7 V.
The motorcycle or car engine should not turn off when the battery is disconnected because the charging system should be able to make enough juice to power the engine and recharge the battery. If it turns off, its indicative a something amiss in the charging system and it could be what ruined your battery to start. I don't do motorcycles, so there can be something I don't know about them, but otherwise have dealt with this stuff before.

I will say, its usually NOT advisable to disconnect the battery you are removing part of the circuit, and because of this, it can cause a spike in voltage that MAY/MAYNOT cause an issue in your other electrical components. With that said, I do it all the time but only briefly(Never done it on bikes).

Roberto
 

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The motorcycle or car engine should not turn off when the battery is disconnected because the charging system should be able to make enough juice to power the engine and recharge the battery. If it turns off, its indicative a something amiss in the charging system and it could be what ruined your battery to start. I don't do motorcycles, so there can be something I don't know about them, but otherwise have dealt with this stuff before.

I will say, its usually NOT advisable to disconnect the battery you are removing part of the circuit, and because of this, it can cause a spike in voltage that MAY/MAYNOT cause an issue in your other electrical components. With that said, I do it all the time but only briefly(Never done it on bikes).

Roberto
If it's not charging the battery and doesn't continue to run when jumped try the voltage regulator.
 

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The motorcycle or car engine should not turn off when the battery is disconnected because the charging system should be able to make enough juice to power the engine and recharge the battery. If it turns off, its indicative a something amiss in the charging system and it could be what ruined your battery to start. I don't do motorcycles, so there can be something I don't know about them, but otherwise have dealt with this stuff before.

I will say, its usually NOT advisable to disconnect the battery you are removing part of the circuit, and because of this, it can cause a spike in voltage that MAY/MAYNOT cause an issue in your other electrical components. With that said, I do it all the time but only briefly(Never done it on bikes).

Roberto
The VRSC alternator doesn't produce sufficient current at idle to charge a low battery especially with high draw headlamps or other accessories running. That's why the engine must be run at 3000 RPM when testing for voltage and current on the VRSC charging system. All this info is available in the Harley EDM (electrical diagnostic manual).

My comments about possible damage caused by poor connections to the battery holds for all vehicles with solid state VRs. The resulting voltage spikes if an arc occurs at the connection are not hard to imagine.
 

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Exorcise the electrical gremlins !

I personally do not use a battery tender on my installed battery if the bike is to sit for more than a couple weeks - I simply disconnect the battery to avoid draining. If a longer storage period I remove the battery and trickle charge it on the bench every couple weeks. I've got a Li-Ion Phosphate Earth X now so I'm even more careful with parasitic voltage drain as it can cause the battery to go into self protect mode and then requires a little procedure to recharge it. Having said that a 3 year old battery that even though it has been continuously trickle charged may be smoked inside. Buy a new battery, top charge, install, check the charging as STEVER975 has said and don't disconnect anything while it's running. If the charge voltage is good all will be well. If it still cuts out you have another problem if the battery remains charged after the bike cuts out. 3 year old sealed L/A batteries are subject to failure. I'm seeing how long my Earth X Li-Ion Po will go, I'm hoping twice that with proper care then the lighter battery's 2 times higher cost will be the same as 2 sealed L/A's. :blahblah: :D
 
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