Voltage fluctuations

[102611M]

Hi guys, i've been riding a Kawasaki 09 ER-6F/Ninja 650r for a year plus now and recently i realise the voltage fluctuates from 13.3 ish to 11.5 ish (plus minus 1-2)

 

For example:

 

When i turn my ignition on, the voltmeter shows a steady 12.5-12.7 on a normal day and when i crank and engine on idle voltage goes to 13.1-13.4 and when i ride off it drops abit to 12.6-12.9. Sounds normal right?

 

BUT

 

After riding for awhile like say 10-20 minutes, the voltage while im riding will start to gradually drop to 11.5-12. and then SOMETIMES it will go back up to 12.8-13.2 while riding and then it would drop again and then it would go back up repeatedly, gradually. and let say if i stop to idle after a long 20-30 mins ride, the idling voltage will be around 11.1-11.7. The worst i've seen it go was 10.9.

 

Usually this happens on long 20-40 mins rides. The voltage fluctuations are not so bad on my daily 10-15 mins ride to work, at most it'll drop to around 11.9-12.2 by the time i reach work.

 

I also now frequently (once every 1-2 days) idle my bike so as to charge my battery back up because if not i realise my ignition voltage will drop to 12.4-12.5. If i charge, my ignition voltage will be around 12.6-12.8.

 

Just some additional info:

- my last battery change was around 1 year 6 months ago by previous owner, currently using some lithium battery

- my only electrical accessory is my SPY 2 way alarm, used to have 2 pairs of additional lights but i disconnected them long ago

- recently changed my stock bulbs to Osram night racer

- magnet coil have been changed before in 2011-2012 (previous owner)

 

Anyone with similar experiences? Maybe time for me to change my battery?

Any opinions and suggestions are GREATLY appreciated!

[Tachnicolour]

Hi guys, i've been riding a Kawasaki 09 ER-6F/Ninja 650r for a year plus now and recently i realise the voltage fluctuates from 13.3 ish to 11.5 ish (plus minus 1-2)

 

For example:

 

When i turn my ignition on, the voltmeter shows a steady 12.5-12.7 on a normal day and when i crank and engine on idle voltage goes to 13.1-13.4 and when i ride off it drops abit to 12.6-12.9. Sounds normal right?

 

BUT

 

After riding for awhile like say 10-20 minutes, the voltage while im riding will start to gradually drop to 11.5-12. and then SOMETIMES it will go back up to 12.8-13.2 while riding and then it would drop again and then it would go back up repeatedly, gradually. and let say if i stop to idle after a long 20-30 mins ride, the idling voltage will be around 11.1-11.7. The worst i've seen it go was 10.9.

 

Usually this happens on long 20-40 mins rides. The voltage fluctuations are not so bad on my daily 10-15 mins ride to work, at most it'll drop to around 11.9-12.2 by the time i reach work.

 

I also now frequently (once every 1-2 days) idle my bike so as to charge my battery back up because if not i realise my ignition voltage will drop to 12.4-12.5. If i charge, my ignition voltage will be around 12.6-12.8.

 

Just some additional info:

- my last battery change was around 1 year 6 months ago by previous owner, currently using some lithium battery

- my only electrical accessory is my SPY 2 way alarm, used to have 2 pairs of additional lights but i disconnected them long ago

- recently changed my stock bulbs to Osram night racer

- magnet coil have been changed before in 2011-2012 (previous owner)

 

Anyone with similar experiences? Maybe time for me to change my battery?

Any opinions and suggestions are GREATLY appreciated!

 

Get your rectifier looked over. There was once a rider from the GSR group which experienced similar problems. Starting voltages were fine, but once the bike got warmed up and hot, the voltage would drop off to below start value, signalling the battery was providing power for the electrical systems and not being charged by the stator(coil).

 

Took awhile, but a shop finally determined there was a hairline crack on the rectifier. When the rectifier was cold, it was problem free. Once it got up to temps and the metal of the rectifier expanded, the crack would open leading to an open circuit internally.

 

That being said, actually when you ride off, your voltage should rise to above your idling voltage. It's unlikely that there's an electrical drain causing your problems as you've indicated that idle voltages after a cold start can be 13.1-13.4. It *could* also be a problem with the coil, where the same heat-induced stress would cause an open circuit, removing it from the charging system after it warms up. The rectifier would not get any supply from the coil and your battery would be providing the electrical supply.

 

I'd say have a reputable shop test your rectifier and coil. See if the coil is putting out the recommended voltages under load and also test the rectifier after it's warmed up.

 

11.1-11.7 means pretty much that your charging system isn't functioning at that point in time.

 

Typical modern coils should have a connector with 3 leads. Name them X Y Z, check X-Y with a multimeter set to AC, then X-Z, then Y-Z. All 3 phases should give approximately the same output at a given engine speed. Check output voltages when cold. If one or two phases are low after the engine is hot, you may have a coil problem(but that's usually a short circuit, not a heat induced open circuit depending on whether it's a wye or delta config). That doesn't mean that the rectifier is fine.

 

If the coil output checks out after bike is hot, then it will most likely be your rectifier. Have to check the output on that as well.

 

I am by no means an electronics expert, I've just had the misfortune of having a coil fail and had to run troubleshooting. Your incident reminds me of the above mentioned GSR case.

 

My guess is rectifier. Since when you move off the voltages drop off below idling voltage straight away. It should usually go upwards. And also due to the fact that it gradually and repeatedly fluctuates high and low. A coil would fail and stay failed when hot. The rectifier might be acting up internally.

 

This is only my opinion and I am in no way saying that it's a confirmed diagnosis. Hope that it'll give you a starting point when you take it to a workshop. Cheers.

Edited October 10, 2015 by Tachnicolour

[kaiq]

Just curious. If the rectifier had a hair line crack, can we seal it with high-temp sealant?

[Tachnicolour]

Just curious. If the rectifier had a hair line crack, can we seal it with high-temp sealant?

 

For weatherproofing? You could, with a neutral-cure one. If it's to solve the above mentioned problem it won't help. Additionally, the example I quoted was just by pure chance they spotted the crack. There are other modes of rectifier failure too.

[102611M]

Get your rectifier looked over. There was once a rider from the GSR group which experienced similar problems. Starting voltages were fine, but once the bike got warmed up and hot, the voltage would drop off to below start value, signalling the battery was providing power for the electrical systems and not being charged by the stator(coil).

 

Took awhile, but a shop finally determined there was a hairline crack on the rectifier. When the rectifier was cold, it was problem free. Once it got up to temps and the metal of the rectifier expanded, the crack would open leading to an open circuit internally.

 

That being said, actually when you ride off, your voltage should rise to above your idling voltage. It's unlikely that there's an electrical drain causing your problems as you've indicated that idle voltages after a cold start can be 13.1-13.4. It *could* also be a problem with the coil, where the same heat-induced stress would cause an open circuit, removing it from the charging system after it warms up. The rectifier would not get any supply from the coil and your battery would be providing the electrical supply.

 

I'd say have a reputable shop test your rectifier and coil. See if the coil is putting out the recommended voltages under load and also test the rectifier after it's warmed up.

 

11.1-11.7 means pretty much that your charging system isn't functioning at that point in time.

 

Typical modern coils should have a connector with 3 leads. Name them X Y Z, check X-Y with a multimeter set to AC, then X-Z, then Y-Z. All 3 phases should give approximately the same output at a given engine speed. Check output voltages when cold. If one or two phases are low after the engine is hot, you may have a coil problem(but that's usually a short circuit, not a heat induced open circuit depending on whether it's a wye or delta config). That doesn't mean that the rectifier is fine.

 

If the coil output checks out after bike is hot, then it will most likely be your rectifier. Have to check the output on that as well.

 

I am by no means an electronics expert, I've just had the misfortune of having a coil fail and had to run troubleshooting. Your incident reminds me of the above mentioned GSR case.

 

My guess is rectifier. Since when you move off the voltages drop off below idling voltage straight away. It should usually go upwards. And also due to the fact that it gradually and repeatedly fluctuates high and low. A coil would fail and stay failed when hot. The rectifier might be acting up internally.

 

This is only my opinion and I am in no way saying that it's a confirmed diagnosis. Hope that it'll give you a starting point when you take it to a workshop. Cheers.

 

Thanks man for the lead, i will get it checked asap and update this thread soon

[102611M]

UPDATE!

 

Surprise surprise, the culprit was indeed the rectifier! It had a hole on the bottom, im guessing it got too hot?

Stator voltage was fine so i had to change the rectifier and battery only. Problem solved!

[tiku]

Care to share which shop u went to solve ur er6f?

[aimnfire]

thats why it good to have voltage indicator on our ride

[Tachnicolour]

UPDATE!

 

Surprise surprise, the culprit was indeed the rectifier! It had a hole on the bottom, im guessing it got too hot?

Stator voltage was fine so i had to change the rectifier and battery only. Problem solved!

Excellent! Glad you managed to get that sorted. Which rectifier didja get ? Shindengen? As for the hole, it depends I suppose. Any pics? If it's a naked bike and the rectifier is exposed and front-facing, could be debris strike. If it's a faired bike or the rectifier is in a sheltered rear area, then yea well, corrosion. It would be quite something to melt a hole through the metal. Although a short-circuit could possibly do that, but you'd prolly have lotsa other problems as well. Might be the lower mounting hole in the cooling fins gave way.

[102611M]

Care to share which shop u went to solve ur er6f?

 

i went to unique motor at woodlands as i live nearby

[102611M]

Excellent! Glad you managed to get that sorted. Which rectifier didja get ? Shindengen? As for the hole, it depends I suppose. Any pics? If it's a naked bike and the rectifier is exposed and front-facing, could be debris strike. If it's a faired bike or the rectifier is in a sheltered rear area, then yea well, corrosion. It would be quite something to melt a hole through the metal. Although a short-circuit could possibly do that, but you'd prolly have lotsa other problems as well. Might be the lower mounting hole in the cooling fins gave way.

 

i got an oem kawa versys rectifier. my rectifier is located beside the rear shock. somewhere near the rear mud guards too. the plastic connector have become very crispy and brittle as what you would expect from plastics that have aged with heat, and the connector broke to pieces when the mech pulled it from the rectifier. so he had to plug in each individual pins one by one without the plastic connector holding the pins together.

[102611M]

 

here's some pics

[Hydher]

thank you for sharing.

 

For a moment.. it sounds like your coil.

 

Mine was a rectifier fault as well. Happens when hot, meter will reset and bulbs blow often.

[Tachnicolour]

[ATTACH=CONFIG]329328[/ATTACH]

[ATTACH=CONFIG]329329[/ATTACH]

[ATTACH=CONFIG]329330[/ATTACH]

 

here's some pics

Wow, that's one toasty rectifier indeed. From the looks of the pic, it seems like some of your connectors have been arcing. It can happen when the spade female-male interface isn't solid. Or when the connectors develop poor conductivity due to glazing/corrosion. Some times the contacts within the plug can wiggle around and actually be a loose fit. If the connectors lose contact but are close enough at high vibrations, it can result in a spark arcing and may lead to glazing of the contacts, resulting in poor connectivity and further arcing.

 

Just monitor the wires connected to your rectifier. They should get warm but not hot. If any of them are too hot to touch after the bike is off, you might want to cut off and redo the connector.

[102611M]

thank you for sharing.

 

For a moment.. it sounds like your coil.

 

Mine was a rectifier fault as well. Happens when hot, meter will reset and bulbs blow often.

 

You're very welcome Glad i could share my experience

[102611M]

Wow, that's one toasty rectifier indeed. From the looks of the pic, it seems like some of your connectors have been arcing. It can happen when the spade female-male interface isn't solid. Or when the connectors develop poor conductivity due to glazing/corrosion. Some times the contacts within the plug can wiggle around and actually be a loose fit. If the connectors lose contact but are close enough at high vibrations, it can result in a spark arcing and may lead to glazing of the contacts, resulting in poor connectivity and further arcing.

 

Just monitor the wires connected to your rectifier. They should get warm but not hot. If any of them are too hot to touch after the bike is off, you might want to cut off and redo the connector.

 

Hmm, what happens when it arcs? any significant effect that might have?

 

Recently i've noticed sometimes my voltage would drop regardless of idling or on the move. when idling it would drop from 13+ to 11.9-12+. when riding i've seen it go as low as 12.9. is that normal? It would also go back to normal after sometime and drop again after some time. Overall, my battery voltage every morning doesnt drop below 12.5 when i turn my key to ignition. i've been monitoring it for some time now because it doesnt seem to be draining my battery so im not too worried about it but im just very very curious if that normal

[Hydher]

Happened to me that the voltmeter was showing an innacurate reading after a short circuit.

 

I use dielectric grease to resist corrosion

[Tachnicolour]

Hmm, what happens when it arcs? any significant effect that might have?

 

Recently i've noticed sometimes my voltage would drop regardless of idling or on the move. when idling it would drop from 13+ to 11.9-12+. when riding i've seen it go as low as 12.9. is that normal? It would also go back to normal after sometime and drop again after some time. Overall, my battery voltage every morning doesnt drop below 12.5 when i turn my key to ignition. i've been monitoring it for some time now because it doesnt seem to be draining my battery so im not too worried about it but im just very very curious if that normal

 

As above. Arcing can result in glazed contacts. E.g. connectors become glazed and preventing a good connection. This can lead to further arcing.

 

If you have just changed your rectifier and you're still seeing the symptoms you mentioned above, you might want to see if the rectifier gets too hot to touch or if any of the wires are heating up. Could be the connectors are corroded/pitted from the earlier burnout. Firstly though, check with a DMM against your voltmeter, across the battery. Especially when you experience a voltage drop after bike is hot and running, see if your voltmeter is functioning properly.

 

It's not normal. The RR + stator, if doing their jobs properly, should give you a pretty smooth 13.X+to 14.X+ without any appreciable spikes, should never go above 15V. As mentioned, check with a DMM. It depends what your voltmeter is connected to.

[102611M]

okay i found out why my voltage fluctuates. after observing for weeks i realise the voltage drops when the cooling fan turns on. I've read that the cooling fan does draw a significant amount of current but what is considered normal? idling w/o fan: 13-13.4 idling with fan:12-12.5 is this considered normal?

[Tachnicolour]

okay i found out why my voltage fluctuates. after observing for weeks i realise the voltage drops when the cooling fan turns on. I've read that the cooling fan does draw a significant amount of current but what is considered normal? idling w/o fan: 13-13.4 idling with fan:12-12.5 is this considered normal?

 

That's not too bad then. 13-13.4. It could be a voltmeter inaccuracy, or it could be also that the voltmeter is tapped to your headlight, which would result in a lower than battery reading. If the fan kicks in, possible that that's the results you're seeing. Best is to check across the battery with a DMM. When the bike is running and warmed up.

[102611M]

ahh alright, thanks man! will do!