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Offline Shed

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #10 on: 11 October, 2020, 11:30:45 PM »
*Originally Posted by BigGinger [+]
Iím not inclined to say the stator is knackered and I donít believe the rectifier is dead either. Maybe the stator is beginning to let go. Iím not expert so At this point Iím just frustrated with a lack of an answer as to why it died after an hour of riding.
Electrexworld has a stator for £114 so itís not the end of the world if thatís whatís wrong. I just donít want to waste money on something I donít actually need.

As Art says above, you need logical steps. A bit of patience! It is frustrating, but try not to be tempted with this, that, and the other, or rushed guesswork, otherwise you could be playing an expensive game of 'parts-darts'. The charging system is exactly that, a system. One thing effects another, effects another and so on. Test each part of it methodically, otherwise you may find yourself replacing what is actually a symptom, and the not replacing what is actually the cause.

I think you're definitely on the undercharging side. Clean, inspect all the wiring as you go along testing it. Get the RR off, clean up the ground points while you are there. Poor connections give misleading readings. Clean up. Retest.  We'll get it sussed. :028:

Offline Shed

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #11 on: 11 October, 2020, 11:35:06 PM »
*Originally Posted by Bikermike1 [+]
Found this link very helpful when I was having charging system problems. https://vfrworld.com/threads/how-to-fix-common-regulator-stator-failures.39277/

Nice one Mike, I'll have a read in there and see what comes out in the wash.

Although, as there's 21 pages to sift through,  :035: It'll be tomorrow  :028:

Offline BigGinger

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #12 on: 15 October, 2020, 07:00:53 PM »
Hey guys. Havenít yet looked at possible cause of my problem but Iím not working this weekend so Iím sure Iíll get round to it.

Question - I believe the alternator burns out due to lack of oil to cool it down. If I were to use thinner oil, would it help at all? Not so thin as to be bad for the engine, but thinner than 10W40...

Offline angelin

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #13 on: 15 October, 2020, 07:33:42 PM »

the cbf generator has little power and is under dimensioned for the current loads fuel pump fuel system efi headlights then heated fan grips surely exceed 330 w. and the engine revolutions are not always at 5000 rpm and so the generator heats up. and burns. I think it's just for that. :431:

Offline BigGinger

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #14 on: 15 October, 2020, 07:41:46 PM »
SIGHHHH

I love the bike. I love the torque. I love that it carries a pillion without skipping a beat. Iíve only had it since late June and the last owner had fitted a new regulator and stator within the last 5-10,000 miles at my best recollection. Iím still not sure whatís wrong with the charging system but if itís either one of those, thatís just not good enough. I may well end up selling it. Any recommendations for what could replace it? Keep in mind Iím 26 and insurance is looking for any reason to rob me blind.


This weekend Iíll see what the voltage reads on the battery when starting the engine and Iíll check the resistance from the stator and find out how to test a regulator.

Offline angelin

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #15 on: 15 October, 2020, 08:00:08 PM »

check the 3 wires coming out of the stator that they are not grounded check the continuity of the 3 stator wires between them that the resistance is the same check the battery ground and regulator ground that it is good check the cable that goes from the regulator to the battery in good condition and that it makes a good contact. then check the cable coming from the ignition lock positive that you must have attention when you turn on the key +15 if everything is regular probably defective regulator :405:

Offline Art

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #16 on: 16 October, 2020, 07:35:35 AM »
*Originally Posted by angelin [+]
the cbf generator has little power and is under dimensioned for the current loads fuel pump fuel system efi headlights then heated fan grips surely exceed 330 w. and the engine revolutions are not always at 5000 rpm and so the generator heats up. and burns. I think it's just for that. :431:

The Charging System doesn't work like that. The battery is the key component that supplies the electrics, it is the buffer or reserve tank of the charging system as well as the weakest link. The stator output is 344W for the SC58 (MKI) or 350W for the SC64 (MKII) and even at low RPM it should be able to keep pace with the electrical loading on the battery. To test your particular set up of accessories and add ons turn everything on and leave the engine on tickover until the fan kicks in. Then using a multimeter check the voltage across the battery terminals while slowly increasing the engine RPM and noting at what RPM the charging voltage reaches 13.2v.

Offline BigGinger

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #17 on: 16 October, 2020, 07:41:28 AM »
Am I looking for 13.2v because thatís what I got last time? Iíd be a lot more comfortable with 14v or so. Iím not riding around at 3-5k revs constantly, just because Iím paranoid Iíll end with a dead battery if I donít.

Offline Art

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #18 on: 16 October, 2020, 07:47:57 AM »
*Originally Posted by angelin [+]
check the 3 wires coming out of the stator that they are not grounded check the continuity of the 3 stator wires between them that the resistance is the same check the battery ground and regulator ground that it is good check the cable that goes from the regulator to the battery in good condition and that it makes a good contact. then check the cable coming from the ignition lock positive that you must have attention when you turn on the key +15 if everything is regular probably defective regulator :405:

Putting some meat on the bones or just a translation...
Stator coil resistance between each pairing of the three yellow cables (stator coils) from the stator should be equal and in the range 0.1Ω to 1.0Ω.
Voltage drop between battery negative to regulator/rectifier green cable should be less than 0.2v
Voltage drop between battery positive to regulator/rectifier red cable should be less than 0.2v
If the regulator/rectifier out put voltage is greater than 15v it is defective

Offline BigGinger

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Re: Flat battery. Alternator, rectifier or battery?!!
« Reply #19 on: 16 October, 2020, 07:53:39 AM »
Would it need to produce 15v across the battery terminals? Thatís the bit Iím confused about. At no point have I seen anything that high.