Charge voltages

[bikemad62]

I recently had a flat battery. First ever lol but i think my regulator is dying. Does anyone know charging voltages lights on, lights off etc. Upon first investigation i found a burn mark on the plug of the regulator. This i have sorted by removing the offending pin. and replacing with a new one. But i'm not sure if my voltages are correct. Its a 2002 foxeye which if i have read correctly got stronger electrics to cope with the extra permanent dip beam.
Lights off  14.02v
Lights on  13.05v
Ign only  12.5v
Ign off  12.7v
Thanks in advance.

[Fazerider]

At first sight I can't see anything suggesting a duff regulator there, but it depends what your engine revs were.
The output of the generator rises with rpm and the excess power is dissipated by the regulator- if it's faulty the voltage can get too high.  14V is OK, but what is it at 10,000 rpm?

[69oldskool]

 
 
Factory manual specs 14.1-14.9v no load voltage for regulator, & 12.8v for battery (no load).& a 0.2-2.5v rise from this when charging.
 
Your Supposed to check charging circuit @ 5000rpm. This can be quite disconcerting for anyone even slightly mechanically sympathetic.(seen it done in bike shop  )
 
Quick & dirty~I've allways blipped the throttle with the lights on & watched for the flicker as the reg. kicks in & out.
 
FWIW, i suspect your regs not "dying" a long lingering death   , its most likely either DEAD or ALIVE.
 
May be as well to check your alternator windings & all the other wiring connections associated with the charging circuit as that burnt pin's telling you something.
 
Hope that helps, not sure it does.
 
 
 

[Major Rant]

He's right ... nothing there to suggest a duff regulator.
 
There are whole host of things that can go wrong with a battery that can make you think its duff. Some have "causes" and some just happen with age.
It can get 1 cell shagged - makes a 10V battery- usually caused by letting it sit in a discharged state for too long.
It can go low capacity - usually caused by overcharging.
It can go high resistance - usually an age related thing.
 
The first thing I would check is the capacity of the battery. It should be 10 Amp Hours or so and they can degrade to about 1.5 Amp Hours without you really noticing and then suddenly you get out there on a cold morning and it won't start the bike.
 
First thing to do is to make sure its fully charged without overcharging it. The bike will do that for you or you can do it with a charger by monitoring the voltage when its charging.
At a moderate charge current (say 1.0 Amp or 0.5 Amp) the thing is 90 percent charged when it reaches 13.5V.
If you keep charging it beyond 13.5V it will quickly rise to 14.3V and sit there creating Hydrogen and Oxygen and degrading itself.
 
Once you've got it to 13.5V then leave it for a couple of hours and it should "relax" to about 12.8V....
 
Then drain it (but don't fully discharge it cos that can damage them). Turn the ignition on, make sure the kill switch is set to "engine off" and then turn on the headlight (one bulb only)
Thats 5 amps and you can add 1 amp for the tail light and side light.
if it can drive that lot for 30 mins without going orange then you have at least a 3 amp hour battery and it should start the bike after its been fully charged again.
60 minutes is good.
90 minutes is a new battery.
 
If the battery voltage falls below 11V under headlight load (lights go orange) then stop - its nearly discharged and you may damage it.
 
Never try to start the bike with a discharged battery - they REALLY don't like that (especially GEL batteries as were fitted OEM to Mk1 Fazers)

[bikemad62]

Thanks for all your help and advice. I went over the wiring and to my surprise I found a burn on the plug of the regulator. pulled it apart and one of the three wihite wires from the generator came out of its terminal. I can only assume this has been going on for a while. I  had to cut back quite a way to find good copper to solder to. But I grafted a new piece of wire and connector then carefully teased the other end of the block plug connector out. Then soldered a new connector on that. plugged it back in and normal service has been resumed. Though I will be keeping a close eye on that plug in future. Once again many thanks for all your help.