went out today, and the bike wouldnt start after a fuel stop.
breakdown services came and diagnosed a flat battery.
never had any issues at all with the bike, and it allways starts/runs fine.

the recovery guy puts the meter on the bike and it shows 11.5V, with 113cca. puts the jump leads on, and it fires straight away.

charging on tick-over was 12.85 amps, and 1/3 throttle was 13.5 amps.
service book states 14.3 amps at 3000 rpm. these figures were taken on the battery just after the jump start.

as ive no knowledge of electrical systems, if the regulator/rectifier is faulty, would it be slightly off like the figures above, or would the out put be nothing?

im waiting for the harley service tech to call me back, as bike is still under the 2 years warranty.

 

I know next to nothing about all these diagnosis's that are necessary to fix my bike but I'm trying to learn. I hope that this thread gets a lot of replies because this man ask some very good questions that I too would like to know.

 

Typically you will see fluctuation or very low to nothing, but slightly off would not necessarily indicate a bad regulator. It may only be that is all the battery is allowing, I would replace the battery if it does not hold a charge after riding a few miles or so.

 

11.5v is low battery should show 12-13v all the time charging voltage should be 13.5-14v. As the battery reaches full charge the amperage will drop off. It's like filling up the gas tank in your car the battery can only hold so much. give your battery a good charge at least 15 hours then see if you have a problem.

 

These bikes need to be ridden to get a deep cycle charge in the battery. Short rides just offer a "surface" charge. Unlike cars that typically run off the voltage and amps the alternator is providing, Harleys are powered by the battery and all voltage and amps from the alternator go right to the battery.