Agreed not linear, assume 3000rpm..............Seems like a stock charging/vreg with a standard battery works fine unless extra loads are introduced (lights, accessories, etc.). I would not expect a noticeable difference by bumping up the charging voltage (assuming riding at a minimum rpm).
I don't have any idea really. Until I formulate a plan of action for trouble shooting this, I really don't want to start removing bodywork & all its associated screws. Too many little bits to lose if they sit disassembled for any length of time.
First thing I would do is take the battery out and have it load tested. Then I would test the rotor and measure brushes, then I would test the VR.
It was indicated that the charging voltage at the battery (during significant rpm) was just over 13.0V, which points more to a alternator/VR issue and not a battery issue. A weak battery may be the secondary effect. How about starting simple with wire connections and cleaning if necessary.
That depends ... how much is the charging CURRENT (I)? How discharged is the battery (in Ampre hours (Ah))? Then it becomes a simple maths calculation Time = Ah / I You cannot calculate it from voltage alone. You need to know the current involved. You may have an indication of charge remaining in a battery under specific conditions. But you will have no idea of the charge current by measuring the charging voltage. ----------------------------- You can chase around testing things and eventually find what is wrong. Rather random. Some understanding of how it should work would help in finding what is wrong ... There could be significant voltage dropped between the alternator output (diode board) and the battery .. usually bad connections. The voltage regulator could be bad .. or the brushes/rotor ... measuring the voltage on the brushes may indicate how hard the alternator is being driven. ------------------ If it ware a car the first thing an automotive electrician would do is load test the battery. Why? Because it is the simplest quickest cheapest test that they can do and removes a frequently failing component from the possible list of faulty components. The next thing they would test is the alternator charging voltage, if that were faults they'd probable change the alternator .. if that was available speedily. Again because it is the simplest quickest cheapest thing they can do. As a DIY your not paying for labor and don't have the range of parts/tools available that an automotive electrician has. So different methods are used to suit.
Just did a 40-ish mile ride & the indicated voltage steadily increased to a more comfortable figure (12.5 V +-). Add the 1V+- it seems to read low, and it starts to look, well, ok to my way of thinking. Not any more sensible, but better. Thanks for the outline, Hardwaregrrl-- it looks like a good starting point, which was what I was lacking.
To load test it, put your volt meter on the battery and hit the starter. It shouldn't drop below 10v. Sent from my Nexus 7 using Tapatalk
Well if you have a bosch starter and a PC680 it will drop to 9 briefly. but of course.....ymmv I recommend having it tested at a battery/auto parts shop for the best reading.
Actually, I did that accidentally yesterday when I measured the charging voltage: it didn't go below 11 V.
Oh yes. I know what influence a burned-out gen light would have on this, and I would have replaced that immediately had it needed it. Besides, how fun is a simple solution, anyway?
Pull your front cover and check the resistance across the across the two brass rings. You'll need to put a piece of card board under the brushes to get a good reading. I think it should read 3 ohms. There's some years that were different...I can't remember which ones. Maybe someone will chime in with that info. Sent from my Nexus 7 using Tapatalk
Oh yeah...disconnect the battery before you remove the front cover. If you don't, you can short out the diode board on the cover letting out precious blue smoke. Sent from my Nexus 7 using Tapatalk
Got it. Thanks. Since the charging system does indeed seem to be working acceptably, I'm going to sideline tinkering with it for a while until I get these front brakes aligned correctly.